mkfs.f2fs: check zeros in first 16MB for Android

We actually don't need to issue trim on entire disk by checking first
blocks having zeros.

Bug: 138459662
Change-Id: Ibed4a1cf55aad6f023c878d3ad2f9ef512b7968d
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
1 file changed