fix(monitor): drop only passed file openat events for procfs

[AryanBakliwal]

Purpose of PR?:
Earlier, KubeArmor was dropping all file open events in procfs and sysfs for sys_openat syscall in the kprobe which caused the permission denied events as well to be dropped. Due to this, alerts were not pushed for file operation events in these directories. This PR corrects this by flagging the events for procfs and sysfs file open operations in kprobe and checks their return value in kretprobe before dropping them.

Fixes #1911

Does this PR introduce a breaking change?
No

If the changes in this PR are manually verified, list down the scenarios covered::

Additional information for reviewer? :
Mention if this PR is part of any design or a continuation of previous PRs

Checklist:

• Bug fix. Fixes I dont see any reports in relay/karmor #1911
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update
• PR Title follows the convention of <type>(<scope>): <subject>
• Commit has unit tests
• Commit has integration tests

[AryanBakliwal]

@rksharma95 updated to only pass permission denied events to user space for sys_openat in procfs