media: vicodec: make life easier for static analyzers

cppcheck incorrectly produces an error here:
[drivers/media/platform/vicodec/vicodec-core.c:1677]: (error) Pointer addition with NULL pointer.

While this is actually a false positive, it doesn't hurt to
reorder the checks to make the code simpler, handling first
the error patch, where no color or alpha components are there.

Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/platform/vicodec/vicodec-core.c

···
 	kvfree(state->compressed_frame);
 	state->compressed_frame = new_comp_frame;
 
-	if (info->components_num >= 3) {
-		state->ref_frame.cb = state->ref_frame.luma + size;
-		state->ref_frame.cr = state->ref_frame.cb + size / chroma_div;
-	} else {
+	if (info->components_num < 3) {
 		state->ref_frame.cb = NULL;
 		state->ref_frame.cr = NULL;
+		state->ref_frame.alpha = NULL;
+		return 0;
 	}
+
+	state->ref_frame.cb = state->ref_frame.luma + size;
+	state->ref_frame.cr = state->ref_frame.cb + size / chroma_div;
 
 	if (info->components_num == 4)
 		state->ref_frame.alpha =
 			state->ref_frame.cr + size / chroma_div;
 	else
 		state->ref_frame.alpha = NULL;
+
 	return 0;
 }