drm/radeon: Calling object_unrefer() when creating fb failure

commit f2d68cf4 upstream.

When kzalloc() failed in radeon_user_framebuffer_create(), need to
call object_unreference() to match the object_reference().
Signed-off-by: liu chuansheng <chuansheng.liu@intel.com>
Signed-off-by: xueminsu <xuemin.su@intel.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/gpu/drm/radeon/radeon_display.c

@@ -1110,8 +1110,10 @@ radeon_user_framebuffer_create(struct drm_device *dev,
 	}
 
 	radeon_fb = kzalloc(sizeof(*radeon_fb), GFP_KERNEL);
-	if (radeon_fb == NULL)
+	if (radeon_fb == NULL) {
+		drm_gem_object_unreference_unlocked(obj);
 		return ERR_PTR(-ENOMEM);
+	}
 
 	radeon_framebuffer_init(dev, radeon_fb, mode_cmd, obj);