drm/amd/display: Remove unnecessary NULL check

[Why]
new_crtc_state is already dereferenced earlier in the function

[How]
Remove the check

Signed-off-by: Eryk Brol <eryk.brol@amd.com>
Acked-by: Bindu Ramamurthy <bindu.r@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 2c4dbde..8fac611 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -9367,7 +9367,7 @@ static int amdgpu_dm_atomic_check(struct drm_device *dev,
 		if (ret)
 			goto fail;
 
-		if (dm_old_crtc_state->dsc_force_changed && new_crtc_state)
+		if (dm_old_crtc_state->dsc_force_changed)
 			new_crtc_state->mode_changed = true;
 	}