[XFS] growlock should be a mutex

m_growlock only needs plain binary mutex semantics, so use a struct mutex
instead of a semaphore for it.

SGI-PV: 968563
SGI-Modid: xfs-linux-melb:xfs-kern:29512a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 7f671f8..c618f7c 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -384,7 +384,7 @@
 	uint			m_in_maxlevels;	/* XFS_IN_MAXLEVELS */
 	struct xfs_perag	*m_perag;	/* per-ag accounting info */
 	struct rw_semaphore	m_peraglock;	/* lock for m_perag (pointer) */
-	sema_t			m_growlock;	/* growfs mutex */
+	struct mutex		m_growlock;	/* growfs mutex */
 	int			m_fixedfsid[2];	/* unchanged for life of FS */
 	uint			m_dmevmask;	/* DMI events for this FS */
 	__uint64_t		m_flags;	/* global mount flags */