ANDROID: remove unused variable

Checked the variable in f2fs-stable, I think there was a mistake to remove this
line. Let's remove this to sync with -stable.

Bug: 155529912
Fixes: be3bb0da ("Merge 4.19.119 into android-4.19")
Change-Id: I27af455f0c59924d122a782669bac741bd9a82ea
Signed-off-by: Jaegeuk Kim <jaegeuk@google.com>