xfs: Check the return value of xfs_trans_get_buf()

Check the return value of xfs_trans_get_buf() and fail
appropriately.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Alex Elder <aelder@sgi.com>

diff --git a/fs/xfs/xfs_attr_leaf.c b/fs/xfs/xfs_attr_leaf.c
index 8fad960..58c3add 100644
--- a/fs/xfs/xfs_attr_leaf.c
+++ b/fs/xfs/xfs_attr_leaf.c
@@ -2948,6 +2948,8 @@
 			bp = xfs_trans_get_buf(*trans,
 					dp->i_mount->m_ddev_targp,
 					dblkno, dblkcnt, XBF_LOCK);
+			if (!bp)
+				return ENOMEM;
 			xfs_trans_binval(*trans, bp);
 			/*
 			 * Roll to next transaction.