NFSD: Remove trace_nfsd_clid_inuse_err

This tracepoint has been replaced by nfsd_clid_cred_mismatch and
nfsd_clid_verf_mismatch, and can simply be removed.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>