[media] drivers/media/IR/imon.c: Use pr_err instead of err

Use the standard error logging mechanisms.
Add #define pr_fmt(fmt) KBUILD_MODNAME ":%s" fmt, __func__
Remove __func__ from err calls, add '\n', rename to pr_err

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>