NFSD: Fix error return code in nfsd4_interssc_connect()
'status' has been overwritten to 0 after nfsd4_ssc_setup_dul(), this
cause 0 will be return in vfs_kern_mount() error case. Fix to return
nfserr_nodev in this error.
Fixes: f4e44b393389 ("NFSD: delay unmount source's export after inter-server copy completed.") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>