SUNRPC: trace RPC client lifetime events

The "create" tracepoint records parts of the rpc_create arguments,
and the shutdown tracepoint records when the rpc_clnt is about to
signal pending tasks and destroy auths.

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