sunrpc: remove newlines from tracepoints

Tracepoint strings don't require newlines (and in fact, they are
undesirable).

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>