f2fs: check inject_rate validity during configuring

Type of inject_rate is unsigned int, let's check new value's
validity during configuring.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/sysfs.c

@@ -222,6 +222,8 @@ static ssize_t __sbi_store(struct f2fs_attr *a,
 #ifdef CONFIG_F2FS_FAULT_INJECTION
 	if (a->struct_type == FAULT_INFO_TYPE && t >= (1 << FAULT_MAX))
 		return -EINVAL;
+	if (a->struct_type == FAULT_INFO_RATE && t >= UINT_MAX)
+		return -EINVAL;
 #endif
 	if (a->struct_type == RESERVED_BLOCKS) {
 		spin_lock(&sbi->stat_lock);