drm/plane: Fix IS_ERR() vs NULL check in drm_plane_create_hotspot_properties()

The drm_property_create_signed_range() function doesn't return error
pointers it returns NULL on error.  Fix the error checking to match.

Fixes: 8f7179a ("drm/atomic: Add support for mouse hotspots")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Zack Rusin <zack.rusin@broadcom.com>
Link: https://patch.msgid.link/aTB023cfcIPkCsFS@stanley.mountain
Signed-off-by: Maxime Ripard <mripard@kernel.org>

Author: Dan Carpenter

drivers/gpu/drm/drm_plane.c

@@ -338,14 +338,14 @@ static int drm_plane_create_hotspot_properties(struct drm_plane *plane)
 
 	prop_x = drm_property_create_signed_range(plane->dev, 0, "HOTSPOT_X",
 						  INT_MIN, INT_MAX);
-	if (IS_ERR(prop_x))
-		return PTR_ERR(prop_x);
+	if (!prop_x)
+		return -ENOMEM;
 
 	prop_y = drm_property_create_signed_range(plane->dev, 0, "HOTSPOT_Y",
 						  INT_MIN, INT_MAX);
-	if (IS_ERR(prop_y)) {
+	if (!prop_y) {
 		drm_property_destroy(plane->dev, prop_x);
-		return PTR_ERR(prop_y);
+		return -ENOMEM;
 	}
 
 	drm_object_attach_property(&plane->base, prop_x, 0);