sunrpc: Add XPT flags missing from SVC_XPRT_FLAG_LIST
Commit eccbbc7c00a5 ("nfsd: don't use sv_nrthreads in connection
limiting calculations.") and commit 898374fdd7f0 ("nfsd: unregister
with rpcbind when deleting a transport") added new XPT flags but
neglected to update the show_svc_xprt_flags() macro.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>