ocfs2: Fix check of return value of ocfs2_start_trans()

On failure, ocfs2_start_trans() returns values like ERR_PTR(-ENOMEM).
Thus checks for !handle are wrong. Fix them to use IS_ERR().
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

fs/ocfs2/file.c

@@ -247,8 +247,8 @@ int ocfs2_update_inode_atime(struct inode *inode,
 	mlog_entry_void();
 
 	handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
-	if (handle == NULL) {
-		ret = -ENOMEM;
+	if (IS_ERR(handle)) {
+		ret = PTR_ERR(handle);
 		mlog_errno(ret);
 		goto out;
 	}
@@ -312,8 +312,8 @@ static int ocfs2_simple_size_update(struct inode *inode,
 	handle_t *handle = NULL;
 
 	handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
-	if (handle == NULL) {
-		ret = -ENOMEM;
+	if (IS_ERR(handle)) {
+		ret = PTR_ERR(handle);
 		mlog_errno(ret);
 		goto out;
 	}
@@ -1055,8 +1055,8 @@ static int __ocfs2_write_remove_suid(struct inode *inode,
 		   (unsigned long long)OCFS2_I(inode)->ip_blkno, inode->i_mode);
 
 	handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
-	if (handle == NULL) {
-		ret = -ENOMEM;
+	if (IS_ERR(handle)) {
+		ret = PTR_ERR(handle);
 		mlog_errno(ret);
 		goto out;
 	}
@@ -1259,8 +1259,8 @@ static int __ocfs2_remove_inode_range(struct inode *inode,
 	}
 
 	handle = ocfs2_start_trans(osb, OCFS2_REMOVE_EXTENT_CREDITS);
-	if (handle == NULL) {
-		ret = -ENOMEM;
+	if (IS_ERR(handle)) {
+		ret = PTR_ERR(handle);
 		mlog_errno(ret);
 		goto out;
 	}
@@ -1352,8 +1352,8 @@ static int ocfs2_zero_partial_clusters(struct inode *inode,
 		goto out;
 
 	handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
-	if (handle == NULL) {
-		ret = -ENOMEM;
+	if (IS_ERR(handle)) {
+		ret = PTR_ERR(handle);
 		mlog_errno(ret);
 		goto out;
 	}