Default to /data/media/0 unless we define BOARD_HAS_NO_MULTIUSER_SUPPORT
use lstat to check if file exists

this will only probe the symlink instead of the target file
6.43.5
f2fs: enable support config for M8 and Nexus 5

you still need to merge f2fs backward compatibility code for 3.4.0 kernels
fix recursive path creation bug for /data/media/0
6.43.6
enable f2fs config for m7 variants