greybus: operation: fix broken response tracepoint

The response-received tracepoint is currently broken. Instead of parsing
the received message header it was tracing a bunch of zeroed fields from
an uninitialised response buffer.

Fix this by moving the tracepoint after were the response buffer is
initialised.

Fixes: 7cb496e6890e ("greybus: tracing: fix message traces")
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>