Do not check selinux access for PermissionCache

Change to check selinux for PermissionCache failed because
surfaceflinger did not have access to selinuxfs. Based on the
discussion, it would be better to check PermissionCache without any
further access check, as its failure would mean the same. This change
removes additional access check from dump.

Bug: 313804706
Test: com.google.android.selinux.pts.SELinuxTest#scanBugreport passed
from cheetah

Change-Id: I5f6f882e270d71bc1da37360c6512cac66dd04a9