mountd: regression in crossmounts

commit 8e2fb3fc cause a regression in mount export
that are on different local file system.
Exports like (all on different filesystems)

/home *(rw,fsid=0,crossmnt)
/home/fs1 *(rw,crossmnt)
/home/fs1/fs2/fs3 *(rw,nohide)

and then a mount of the root 'mount /home /mnt'
would end up mounting /home/fs1/fs2/fs3 not /home

Reverting the logic of commit 8e2fb3fc until
a better solution can be found for the original
problem.

Signed-off-by: Steve Dickson <steved@redhat.com>