[GFS2] Remove uneeded memory allocation

For every filesystem operation where we need a transaction, we
now make one less memory allocation.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index 2443e9a..c741016 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -360,7 +360,7 @@
 	unsigned int tr_revokes;
 	unsigned int tr_reserved;
 
-	struct gfs2_holder *tr_t_gh;
+	struct gfs2_holder tr_t_gh;
 
 	int tr_touched;