f2fs: fix to check warm_data_age_threshold

hot_data_age_threshold is a non-zero positive number, and
condition 2 includes condition 1, so there is no need to
additionally judge whether t is 0. And let's remove it.
Signed-off-by: Yangtao Li <frank.li@vivo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/sysfs.c

@@ -689,7 +689,7 @@ static ssize_t __sbi_store(struct f2fs_attr *a,
 	}
 
 	if (!strcmp(a->attr.name, "warm_data_age_threshold")) {
-		if (t == 0 || t <= sbi->hot_data_age_threshold)
+		if (t <= sbi->hot_data_age_threshold)
 			return -EINVAL;
 		if (t == *ui)
 			return count;