Use -Werror in frameworks/native/cmds/cmd

* Ignore return value of getfilecon?

Bug: 66996870
Test: build with WITH_TIDY=1
Change-Id: Ic7d67907a1cf0ba415aa0753bbd55bde06c8dd06
Merged-In: I341e6047dbb5b49a92f69df74b073d2f54a7754d
2 files changed