SUNRPC: Trace call_refresh events

Clean up: Replace dprintk call sites.

Note that rpc_call_rpcerror() already has a trace point, so perhaps
adding trace_rpc_refresh_status() isn't necessary. However, it does
report a particular category of error.

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