NFSv4 remove zero number of fs_locations entries error check

[ Upstream commit 90e12a3191040bd3854d3e236c35921e4e92a044 ]

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>