[LTP] [LTP v4 1/5] IMA/ima_keys.sh: Fix policy content check usage

[Petr Vorel]

Hi,

> require_ima_policy_content cannot be used in subshell $() evaluation,
> because tst_brk does not quit the test. It calls cleanup for the
> subshell process and main process then continue:
...

Merged this one to at least fix ima_keys.sh test.
I'll wait little longer before merging the rest of v4 patchset
https://patchwork.ozlabs.org/project/ltp/list/?series=196621

Kind regards,
Petr