NFSv4 remove zero number of fs_locations entries error check

stable inclusion
from linux-4.19.230
commit 152f7db416c4bfcc8fc01e55cae60f63489580fa

--------------------------------

[ Upstream commit 90e12a31 ]

Remove the check for the zero length fs_locations reply in the
xdr decoding, and instead check for that in the migration code.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com>
Signed-off-by: Laibin Qiu <qiulaibin@huawei.com>