drm/amd/display: Remove redundant assignments

[WHAT & HOW]
log2_blk_height and log2_blk_width are assigned to 0 and then
immediately are updated to other values. The assignments to zero are
redudant and removed.

This fixes 18 UNUSED_VALUE issues reported by Coverity.

Reviewed-by: Rodrigo Siqueira <[e-mail]>
Signed-off-by: Alex Hung <[e-mail]>
Signed-off-by: Rodrigo Siqueira <[e-mail]>
Tested-by: Daniel Wheeler <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/display/dc/dml/dcn20/display_rq_dlg_calc_20.c

···
 	blk_bytes = surf_linear ?
 			256 : get_blk_size_bytes((enum source_macro_tile_size) macro_tile_size);
 	log2_blk_bytes = dml_log2((double) blk_bytes);
-	log2_blk_height = 0;
-	log2_blk_width = 0;
 
 	// remember log rule
 	// "+" in log is multiply
···
 			- log2_meta_req_height;
 	meta_req_width = 1 << log2_meta_req_width;
 	meta_req_height = 1 << log2_meta_req_height;
-	log2_meta_row_height = 0;
-	meta_row_width_ub = 0;
 
 	// the dimensions of a meta row are meta_row_width x meta_row_height in elements.
 	// calculate upper bound of the meta_row_width

drivers/gpu/drm/amd/display/dc/dml/dcn20/display_rq_dlg_calc_20v2.c

···
 	blk_bytes = surf_linear ?
 			256 : get_blk_size_bytes((enum source_macro_tile_size) macro_tile_size);
 	log2_blk_bytes = dml_log2((double) blk_bytes);
-	log2_blk_height = 0;
-	log2_blk_width = 0;
 
 	// remember log rule
 	// "+" in log is multiply
···
 			- log2_meta_req_height;
 	meta_req_width = 1 << log2_meta_req_width;
 	meta_req_height = 1 << log2_meta_req_height;
-	log2_meta_row_height = 0;
-	meta_row_width_ub = 0;
 
 	// the dimensions of a meta row are meta_row_width x meta_row_height in elements.
 	// calculate upper bound of the meta_row_width

drivers/gpu/drm/amd/display/dc/dml/dcn21/display_rq_dlg_calc_21.c

···
 	blk_bytes = surf_linear ?
 			256 : get_blk_size_bytes((enum source_macro_tile_size) macro_tile_size);
 	log2_blk_bytes = dml_log2((double) blk_bytes);
-	log2_blk_height = 0;
-	log2_blk_width = 0;
 
 	// remember log rule
 	// "+" in log is multiply
···
 			- log2_meta_req_height;
 	meta_req_width = 1 << log2_meta_req_width;
 	meta_req_height = 1 << log2_meta_req_height;
-	log2_meta_row_height = 0;
-	meta_row_width_ub = 0;
 
 	// the dimensions of a meta row are meta_row_width x meta_row_height in elements.
 	// calculate upper bound of the meta_row_width

drivers/gpu/drm/amd/display/dc/dml/dcn30/display_rq_dlg_calc_30.c

···
 	blk_bytes = surf_linear ?
 		256 : get_blk_size_bytes((enum source_macro_tile_size) macro_tile_size);
 	log2_blk_bytes = dml_log2((double)blk_bytes);
-	log2_blk_height = 0;
-	log2_blk_width = 0;
 
 	// remember log rule
 	// "+" in log is multiply
···
 		- log2_meta_req_height;
 	meta_req_width = 1 << log2_meta_req_width;
 	meta_req_height = 1 << log2_meta_req_height;
-	log2_meta_row_height = 0;
-	meta_row_width_ub = 0;
 
 	// the dimensions of a meta row are meta_row_width x meta_row_height in elements.
 	// calculate upper bound of the meta_row_width

drivers/gpu/drm/amd/display/dc/dml/dcn31/display_rq_dlg_calc_31.c

···
 	log2_blk256_height = dml_log2((double) blk256_height);
 	blk_bytes = surf_linear ? 256 : get_blk_size_bytes((enum source_macro_tile_size) macro_tile_size);
 	log2_blk_bytes = dml_log2((double) blk_bytes);
-	log2_blk_height = 0;
-	log2_blk_width = 0;
 
 	// remember log rule
 	// "+" in log is multiply
···
 	log2_meta_req_width = log2_meta_req_bytes + 8 - log2_bytes_per_element - log2_meta_req_height;
 	meta_req_width = 1 << log2_meta_req_width;
 	meta_req_height = 1 << log2_meta_req_height;
-	log2_meta_row_height = 0;
-	meta_row_width_ub = 0;
 
 	// the dimensions of a meta row are meta_row_width x meta_row_height in elements.
 	// calculate upper bound of the meta_row_width

drivers/gpu/drm/amd/display/dc/dml/dcn314/display_rq_dlg_calc_314.c

···
 	log2_blk256_height = dml_log2((double) blk256_height);
 	blk_bytes = surf_linear ? 256 : get_blk_size_bytes((enum source_macro_tile_size) macro_tile_size);
 	log2_blk_bytes = dml_log2((double) blk_bytes);
-	log2_blk_height = 0;
-	log2_blk_width = 0;
 
 	// remember log rule
 	// "+" in log is multiply
···
 	log2_meta_req_width = log2_meta_req_bytes + 8 - log2_bytes_per_element - log2_meta_req_height;
 	meta_req_width = 1 << log2_meta_req_width;
 	meta_req_height = 1 << log2_meta_req_height;
-	log2_meta_row_height = 0;
-	meta_row_width_ub = 0;
 
 	// the dimensions of a meta row are meta_row_width x meta_row_height in elements.
 	// calculate upper bound of the meta_row_width