Add missing head sys/types.h to Volume.h
 Fix compile error of build with C++

Change-Id: I2dec329d23c2187d878c1244541d627c68c09a69
Signed-off-by: sndnvaps <sndnvaps@gmail.com>
Merge branch 'cm-11.0' of github.com:CyanogenMod/android_system_vold into cm-11.0