opensnoop: fix --cgroupmap with kfunc
opensnoop: fix --cgroupmap with kfunc

Commit c347fe6c9f75 ("Support kfunc in opensnoop.py") introduces an
alternative probe on do_sys_open() with kfuncs instead of kprobes. This
new implementation is used if the kernel supports it. But it removed the
--cgroupmap filter added in commit b2aa29fa3269 ("tools: cgroup
filtering in execsnoop/opensnoop").

This patch adds the --cgroupmap filter in the kfunc implementation.

brendangregg/bcc,tuxology/bcc,brendangregg/bcc,tuxology/bcc,iovisor/bcc,iovisor/bcc,brendangregg/bcc,brendangregg/bcc,iovisor/bcc,iovisor/bcc,tuxology/bcc,tuxology/bcc,tuxology/bcc,brendangregg/bcc,iovisor/bcc