NFSD: Fix TP_printk() format specifier in nfsd_clid_class

Since commit 9a6944fe ("tracing: Add a verifier to check string
pointers for trace events"), which was merged in v5.13-rc1,
TP_printk() no longer tacitly supports the "%.*s" format specifier.

These are low value tracepoints, so just remove them.

Reported-by: David Wysochanski <dwysocha@redhat.com>
Fixes: dd5e3fbc ("NFSD: Add tracepoints to the NFSD state management code")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>