drm/omap: dsi: Rework and remove a few unused variables

Fixes the following W=1 kernel build warning(s):

drivers/gpu/drm/omapdrm/dss/dsi.c: In function ‘_dsi_print_reset_status’:
drivers/gpu/drm/omapdrm/dss/dsi.c:1131:6: warning: variable ‘l’ set but not used [-Wunused-but-set-variable]
drivers/gpu/drm/omapdrm/dss/dsi.c: In function ‘dsi_update’:
drivers/gpu/drm/omapdrm/dss/dsi.c:3943:10: warning: variable ‘dh’ set but not used [-Wunused-but-set-variable]
drivers/gpu/drm/omapdrm/dss/dsi.c:3943:6: warning: variable ‘dw’ set but not used [-Wunused-but-set-variable]

Cc: Tomi Valkeinen <[e-mail]>
Cc: David Airlie <[e-mail]>
Cc: Daniel Vetter <[e-mail]>
Cc: Laurent Pinchart <[e-mail]>
Cc: [e-mail]
Signed-off-by: Lee Jones <[e-mail]>
Reviewed-by: Laurent Pinchart <[e-mail]>
Signed-off-by: Tomi Valkeinen <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/omapdrm/dss/dsi.c

···
 
 static void _dsi_print_reset_status(struct dsi_data *dsi)
 {
-	u32 l;
 	int b0, b1, b2;
 
 	/* A dummy read using the SCP interface to any DSIPHY register is
 	 * required after DSIPHY reset to complete the reset of the DSI complex
 	 * I/O. */
-	l = dsi_read_reg(dsi, DSI_DSIPHY_CFG5);
+	dsi_read_reg(dsi, DSI_DSIPHY_CFG5);
 
 	if (dsi->data->quirks & DSI_QUIRK_REVERSE_TXCLKESC) {
 		b0 = 28;
···
 		void (*callback)(int, void *), void *data)
 {
 	struct dsi_data *dsi = to_dsi_data(dssdev);
-	u16 dw, dh;
 
 	dsi_perf_mark_setup(dsi);
 
···
 	dsi->framedone_callback = callback;
 	dsi->framedone_data = data;
 
-	dw = dsi->vm.hactive;
-	dh = dsi->vm.vactive;
-
 #ifdef DSI_PERF_MEASURE
-	dsi->update_bytes = dw * dh *
+	dsi->update_bytes = dsi->vm.hactive * dsi->vm.vactive *
 		dsi_get_pixel_size(dsi->pix_fmt) / 8;
 #endif
 	dsi_update_screen_dispc(dsi);