drm/amd/display: Simplify bool comparison

Fix the following coccicheck warning:
./drivers/gpu/drm/amd/display/dc/dml/dcn20/display_mode_vba_20.c:3141:30-39:
WARNING: Comparison to bool
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <abaci-bugfix@linux.alibaba.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dml/dcn20/display_mode_vba_20.c

@@ -3138,7 +3138,7 @@ static void CalculateFlipSchedule(
 				4.0 * (TimeForFetchingMetaPTEImmediateFlip / LineTime + 0.125),
 				1) / 4.0;
 
-		if ((GPUVMEnable == true || DCCEnable == true)) {
+		if ((GPUVMEnable || DCCEnable)) {
 			mode_lib->vba.ImmediateFlipBW[0] = BandwidthAvailableForImmediateFlip
 					* ImmediateFlipBytes / TotImmediateFlipBytes;
 			TimeForFetchingRowInVBlankImmediateFlip = dml_max(