security: adjust test on SELinux for kernel threads

The test currently verifies that all processes running in kernel domain
are kernel threads. It also tests that there is at least one such kernel
thread. However the latter test fails inside a child pid namespace since
all kernel threads always reside in the initial pid-namespace. To fix
this breakage remove the test for existence which is anyway not strictly
needed to validate proper SELinux setup.

Change-Id: I438600a875a1ba3af94c5cffa1c183150aa0036a
1 file changed