Replace the macro XFS_BUF_ISPINNED with helper xfs_buf_ispinned

Replace the macro XFS_BUF_ISPINNED with an inline helper function
xfs_buf_ispinned, and change all its usages.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index bdb47b2..76ee2c5 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -2585,7 +2585,7 @@
 	 * If the buffer is pinned then push on the log now so we won't
 	 * get stuck waiting in the write for too long.
 	 */
-	if (XFS_BUF_ISPINNED(bp))
+	if (xfs_buf_ispinned(bp))
 		xfs_log_force(mp, 0);
 
 	/*