nfsd4: delay setting current filehandle till success

Compound processing stops on error, so the current filehandle won't be
used on error.  Thus the order here doesn't really matter.  It'll be
more convenient to do it later, though.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --cc fs/nfsd/nfs4proc.c
Simple merge