Revert -Wall -Werror

Temporarily revert -Wall -Werror on checkseapp.
This is causing a compiler error on darwin SDK builds.

cc1: warnings being treated as errors
external/sepolicy/tools/check_seapp.c: In function 'rule_map_free':
external/sepolicy/tools/check_seapp.c:439: warning: unused parameter 's'
make: *** [out/host/darwin-x86/obj/EXECUTABLES/checkseapp_intermediates/check_seapp.o] Error 1

Change-Id: I9776777a751f16d5ca0d90e731482c31dac813f9