Fix remaining bionic warnings

smemcap: uid_t is unsigned,
and will change again...

Tested on arm and x86 (kitkat),
aosp/master has some other ones

Change-Id: I170b16f2e091b99f971fb518bf0106c0e92adfdd
Fix other warnings no more shown in 1.23

Change-Id: Ie402a35cc68b63e4e6ff45e91de48b2670d1ffa9