xprtrdma: Clean up tracepoints in the reply path

Replace unnecessary display of kernel memory addresses.

Also, there are no longer any trace_xprtrdma_defer_cmp() call sites.
And remove the trace_xprtrdma_leaked_rep() tracepoint because there
doesn't seem to be an overwhelming need to have a tracepoint for
catching a software bug that has long since been fixed.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>