AOSP: Use -Wno-pointer-arith in Android build

Some "arithmetic on a void pointer is a GNU extension" warnings were
introduced into upstream e2fsprogs, but they are of questionable value,
so disable them for now.

Change-Id: I19e99382e9434828927c1b8287b91f3333110151
From AOSP commit: f203c38fd43dc384cedfcaeb155771a15906022f
1 file changed