gfs2: Fix refcount leak in gfs2_glock_poke

In gfs2_glock_poke, make sure gfs2_holder_uninit is called on the local
glock holder.  Without that, we're leaking a glock and a pid reference.

Fixes: 9e8990d ("gfs2: Smarter iopen glock waiting")
Cc: stable@vger.kernel.org # v5.8+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

fs/gfs2/glock.c

@@ -790,9 +790,11 @@ static void gfs2_glock_poke(struct gfs2_glock *gl)
 	struct gfs2_holder gh;
 	int error;
 
-	error = gfs2_glock_nq_init(gl, LM_ST_SHARED, flags, &gh);
+	gfs2_holder_init(gl, LM_ST_SHARED, flags, &gh);
+	error = gfs2_glock_nq(&gh);
 	if (!error)
 		gfs2_glock_dq(&gh);
+	gfs2_holder_uninit(&gh);
 }
 
 static bool gfs2_try_evict(struct gfs2_glock *gl)