GFS2: Fix gl_object warnings

The following cleanup is needed to avoid spilling the syslog with
false warnings.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

fs/gfs2/rgrp.c

@@ -705,7 +705,7 @@ void gfs2_clear_rgrpd(struct gfs2_sbd *sdp)
 		rb_erase(n, &sdp->sd_rindex_tree);
 
 		if (gl) {
-			glock_set_object(gl, NULL);
+			glock_clear_object(gl, rgd);
 			gfs2_glock_put(gl);
 		}