Privileged usage not correctly detected

[GamerBene19]

This image fails to start with with --privileged (at least in my docker environments).

The issue seems to be the output of capsh --print in this case. This line in the entrypoint script isn't able to handle the capsh output in the privileged case.

Compare

[~] * docker run --rm --cap-add SYS_ADMIN -it  alpine:latest sh
/ # apk add --no-cache --update libcap
...
OK: 8 MiB in 19 packages
/ # capsh --print
Current: cap_chown,cap_dac_override,cap_fowner,cap_fsetid,cap_kill,cap_setgid,cap_setuid,cap_setpcap,cap_net_bind_service,cap_net_raw,cap_sys_chroot,cap_sys_admin,cap_mknod,cap_audit_write,cap_setfcap=ep
...

to

[~] * docker run --rm --privileged -it alpine:latest sh
/ # apk add --no-cache --update libcap
...
OK: 8 MiB in 19 packages
/ # capsh --print
Current: =ep
...

As far as I understand =ep more or less indicates "everything is allowed" see here.
Thereby, I think the simplest fix is to add another check to the function like so

  if capsh --print | grep -Eq "^Current: =ep"; then
    return 0
  fi

but I might be overlooking something, that's why I've opened this issue.