ocfs2: return ENOMEM when sb_getblk() fails

The only reason for sb_getblk() failing is if it can't allocate the
buffer_head.  So return ENOMEM instead when it fails.

[joseph.qi@huawei.com: ocfs2_symlink_get_block() and ocfs2_read_blocks_sync() and ocfs2_read_blocks() need the same change]
Signed-off-by: Rui Xiang <rui.xiang@huawei.com>
Reviewed-by: Jie Liu <jeff.liu@oracle.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c
index 0022192..70d083e 100644
--- a/fs/ocfs2/refcounttree.c
+++ b/fs/ocfs2/refcounttree.c
@@ -1310,7 +1310,7 @@
 
 	new_bh = sb_getblk(sb, blkno);
 	if (new_bh == NULL) {
-		ret = -EIO;
+		ret = -ENOMEM;
 		mlog_errno(ret);
 		goto out;
 	}
@@ -1561,7 +1561,7 @@
 
 	new_bh = sb_getblk(sb, blkno);
 	if (new_bh == NULL) {
-		ret = -EIO;
+		ret = -ENOMEM;
 		mlog_errno(ret);
 		goto out;
 	}
@@ -3029,7 +3029,7 @@
 	for (i = 0; i < blocks; i++, old_block++, new_block++) {
 		new_bh = sb_getblk(osb->sb, new_block);
 		if (new_bh == NULL) {
-			ret = -EIO;
+			ret = -ENOMEM;
 			mlog_errno(ret);
 			break;
 		}