net/mlx5: fix build with clang 14

[ upstream commit bae645a ]

Use fgets instead of fscanf to resolve the following warning
reported by clang 14.0.0 in Fedora 37 (Rawhide):

drivers/net/mlx5/linux/mlx5_ethdev_os.c:1137:52: error:
  'fscanf' may overflow; destination buffer in argument 3 has size 16,
  but the corresponding specifier may require size 17
  [-Werror,-Wfortify-source]
  ret = fscanf(file, "%" RTE_STR(IF_NAMESIZE) "s", port_name);

Fixes: 63d1db7 ("net/mlx5: fix unlimited parsing of switch info")

Signed-off-by: Ali Alnubani <alialnu@nvidia.com>
Acked-by: Thomas Monjalon <thomas@monjalon.net>
Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>

drivers/net/mlx5/linux/mlx5_ethdev_os.c

@@ -1118,7 +1118,6 @@ mlx5_sysfs_switch_info(unsigned int ifindex, struct mlx5_switch_info *info)
 	bool port_switch_id_set = false;
 	bool device_dir = false;
 	char c;
-	int ret;
 
 	if (!if_indextoname(ifindex, ifname)) {
 		rte_errno = errno;
@@ -1134,10 +1133,9 @@ mlx5_sysfs_switch_info(unsigned int ifindex, struct mlx5_switch_info *info)
 
 	file = fopen(phys_port_name, "rb");
 	if (file != NULL) {
-		ret = fscanf(file, "%" RTE_STR(IF_NAMESIZE) "s", port_name);
-		fclose(file);
-		if (ret == 1)
+		if (fgets(port_name, IF_NAMESIZE, file) != NULL)
 			mlx5_translate_port_name(port_name, &data);
+		fclose(file);
 	}
 	file = fopen(phys_switch_id, "rb");
 	if (file == NULL) {