[PATCH net-next] net/mlxfw: fix a NULL dereference

[Dan Carpenter]

If we hit this error path we end up returning ERR_PTR(0) which is NULL.
The caller is not expecting that so it results in a NULL dereference.

Fixes: 410ed13cae39 ("Add the mlxfw module for Mellanox firmware flash process")
Signed-off-by: Dan Carpenter <dan.carpen...@oracle.com>

diff --git a/drivers/net/ethernet/mellanox/mlxfw/mlxfw_mfa2.c 
b/drivers/net/ethernet/mellanox/mlxfw/mlxfw_mfa2.c
index 628150d28061..993cb5ba934e 100644
--- a/drivers/net/ethernet/mellanox/mlxfw/mlxfw_mfa2.c
+++ b/drivers/net/ethernet/mellanox/mlxfw/mlxfw_mfa2.c
@@ -594,6 +594,7 @@ struct mlxfw_mfa2_component *
        if (memcmp(comp_data->buff, mlxfw_mfa2_comp_magic,
                   mlxfw_mfa2_comp_magic_len) != 0) {
                pr_err("Component has wrong magic\n");
+               err = -EINVAL;
                goto err_out;
        }