[GFS2] fix GFP_KERNEL misuses

There are several places where GFP_KERNEL allocations happen under a glock,
which will result in hangs if we're under memory pressure and go to re-enter the
fs in order to flush stuff out.  This patch changes the culprits to GFS_NOFS to
keep this problem from happening.  Thank you,

Signed-off-by: Josef Bacik <jbacik@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/recovery.c b/fs/gfs2/recovery.c
index 06dcdc0..2888e4b 100644
--- a/fs/gfs2/recovery.c
+++ b/fs/gfs2/recovery.c
@@ -68,7 +68,7 @@
 		return 0;
 	}
 
-	rr = kmalloc(sizeof(struct gfs2_revoke_replay), GFP_KERNEL);
+	rr = kmalloc(sizeof(struct gfs2_revoke_replay), GFP_NOFS);
 	if (!rr)
 		return -ENOMEM;