ksmbd: fix error code overwriting in smb2_get_info_filesystem()

If client doesn't negotiate with SMB3.1.1 POSIX Extensions,
then proper error code won't be returned due to overwriting.

Return error immediately.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: e2f3448 ("cifsd: add server-side procedures for SMB3")
Cc: stable@vger.kernel.org
Signed-off-by: Matvey Kovalev <matvey.kovalev@ispras.ru>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

Author: Matvey Kovalev

fs/smb/server/smb2pdu.c

@@ -5629,7 +5629,8 @@ static int smb2_get_info_filesystem(struct ksmbd_work *work,
 
 		if (!work->tcon->posix_extensions) {
 			pr_err("client doesn't negotiate with SMB3.1.1 POSIX Extensions\n");
-			rc = -EOPNOTSUPP;
+			path_put(&path);
+			return -EOPNOTSUPP;
 		} else {
 			info = (struct filesystem_posix_info *)(rsp->Buffer);
 			info->OptimalTransferSize = cpu_to_le32(stfs.f_bsize);