f2fs: check blkaddr more accuratly before issue a bio

commit 0833721ec3658a4e9d5e58b6fa82cf9edc431e59 upstream.

This patch check blkaddr more accuratly before issue a
write or read bio.

Signed-off-by: Yunlei He <heyunlei@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
[bwh: Backported to 4.9: adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>