greybus: svc: Pass the correct pointer to input_free_device()

In gb_svc_input_create() fn, on failure, wrong pointer
was being passed to input_free_device(). Correct it.

svc->input gets initialized only on successful return of this fn,
so it is absolutely wrong to pass svc->input to input_free_device().

Testing Done: Tested on EVT2.0 platform.

Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>