[media] lirc_zilog: Use __func__ for logging function name

Fix all checkpatch reported issues for "CHECK: Prefer using '"%s...",
__func__' to using '<func_name>', ..."

Use recommended style. Additionally, __func__ was already used in
similar cases throughout the code, so make it all consistent.

Signed-off-by: Ricardo Silva <rjpdasilva@gmail.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>