Get the correct fstab entry if there are more than one

vold currently uses the first fstab entry for moun point /data .
However, if there are multiple fstab entries for /data and the
first one isn't the entry actually being used, checkpoint may fail.

Test: boot a device with ext4 entry placed after f2fs
Bug: 293313353
Change-Id: Id374c622c53fd61047d62743555234d36bd038ec
1 file changed