f2fs: ensure minimum trim granularity accounts for all devices

f2fs: ensure minimum trim granularity accounts for all devices

When F2FS uses multiple block devices, each device may have a
different discard granularity. The minimum trim granularity must be
at least the maximum discard granularity of all devices, excluding
zoned devices. Use max_t instead of the max() macro to compute the
maximum value.

Signed-off-by: Yongpeng Yang <yangyongpeng@xiaomi.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>