drm/radeon: Drop unnecessary unsigned int < 0 check

Unsigned integers can never be negative, so drop this check.

Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/radeon_kms.c

@@ -759,7 +759,7 @@ u32 radeon_get_vblank_counter_kms(struct drm_device *dev, unsigned int pipe)
 	u32 count;
 	struct radeon_device *rdev = dev->dev_private;
 
-	if (pipe < 0 || pipe >= rdev->num_crtc) {
+	if (pipe >= rdev->num_crtc) {
 		DRM_ERROR("Invalid crtc %u\n", pipe);
 		return -EINVAL;
 	}