pkg/report: fix corrupted stack trace checking

We started detecting all kernel reboots as corrupted,
because we considered that after any "Allocated" line
a stack trace should follow.
Kernel boot output now contains:
ima: Allocated hash algorithm: sha256
and there is no stack trace after that.

1. Refine stack trace regexps (we actually want to look for
"Allocated by task PID:" lines).
2. Don't check stacks if report format says that it
does not contain stacks.

0 files changed, 0 insertions, 0 deletions