Fixed https://bugzilla.kernel.org/show_bug.cgi?id=202935 allow write on the same file

Copychunk allows source and target to be on the same file.
For details on restrictions see MS-SMB2 3.3.5.15.6

Signed-off-by: Kovtunenko Oleksandr <alexander198961@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifs/cifsfs.c

@@ -1070,11 +1070,6 @@ ssize_t cifs_file_copychunk_range(unsigned int xid,
 
 	cifs_dbg(FYI, "copychunk range\n");
 
-	if (src_inode == target_inode) {
-		rc = -EINVAL;
-		goto out;
-	}
-
 	if (!src_file->private_data || !dst_file->private_data) {
 		rc = -EBADF;
 		cifs_dbg(VFS, "missing cifsFileInfo on copy range src file\n");