dibusb: fix possible memory leak in dibusb_rc_query()

dibusb: fix possible memory leak in dibusb_rc_query()

commit 1f5ecaf985c46889278f51fcb7bc143f60f4eb14 upstream.

'buf' is malloced in dibusb_rc_query() and should be freed before
leaving from the error handling cases, otherwise it will cause
memory leak.

Fixes: ff1c123545d7 ("[media] dibusb: handle error code on RC query")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>