[PATCH net] net/mlx5: Fix uninitialized variable bug in outlen_write()

[YueHaibing]

If sscanf() return 0, outlen is uninitialized and used in kzalloc(),
this is unexpected. We should return -EINVAL if the string is invalid.

Fixes: e126ba97dba9 ("mlx5: Add driver for Mellanox Connect-IB adapters")
Signed-off-by: YueHaibing <yuehaibing@xxxxxxxxxx>
---
 drivers/net/ethernet/mellanox/mlx5/core/cmd.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
index 2e0d59ca62b5..cfb1e9f18a6c 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
@@ -1508,8 +1508,8 @@ static ssize_t outlen_write(struct file *filp, const char __user *buf,
 		return -EFAULT;
 
 	err = sscanf(outlen_str, "%d", &outlen);
-	if (err < 0)
-		return err;
+	if (err != 1)
+		return -EINVAL;
 
 	ptr = kzalloc(outlen, GFP_KERNEL);
 	if (!ptr)
-- 
2.17.1