Fix static analyzer warnings.

Fix the following warnings:

system/sepolicy/tools/sepolicy-analyze/neverallow.c:346:9: warning:
Potential leak of memory pointed to by '__s1'
system/sepolicy/tools/sepolicy-analyze/neverallow.c:346:9: warning:
Potential leak of memory pointed to by 'id'
system/sepolicy/tools/sepolicy-analyze/neverallow.c:364:13: warning:
Potential leak of memory pointed to by 'classperms'
system/sepolicy/tools/sepolicy-analyze/neverallow.c:364:13: warning:
Potential leak of memory pointed to by 'node'

Bug: b/27101951
Test:Warnings are gone.
Change-Id: Ib9b2e0b9f19950b4b764d438ee58340e6c022ef5