nfsd: remove some unnecessary dropit handling

We no longer need a few of these special cases.

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

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

diff --cc fs/nfsd/nfs4state.c
Simple merge

diff --cc fs/nfsd/nfs4xdr.c
Simple merge

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