cifs: Fix xid leak in cifs_get_file_info_unix()

If stardup the symlink target failed, should free the xid,
otherwise the xid will be leaked.

Fixes: 76894f3e ("cifs: improve symlink handling for smb2+")
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifs/inode.c

@@ -368,8 +368,10 @@ cifs_get_file_info_unix(struct file *filp)
 
 	if (cfile->symlink_target) {
 		fattr.cf_symlink_target = kstrdup(cfile->symlink_target, GFP_KERNEL);
-		if (!fattr.cf_symlink_target)
-			return -ENOMEM;
+		if (!fattr.cf_symlink_target) {
+			rc = -ENOMEM;
+			goto cifs_gfiunix_out;
+		}
 	}
 
 	rc = CIFSSMBUnixQFileInfo(xid, tcon, cfile->fid.netfid, &find_data);