Fix building with clang-16, as lot of functions from string.h (including
memset) couldn't be found. Resulting in error: call to undeclared library
function memset type error.
Bug: https://bugs.gentoo.org/898550
--- a/port-helper/port-helper.c
+++ b/port-helper/port-helper.c
@@ -13,6 +13,7 @@ for read and write, and the console is functional.
 #include <stdio.h>
 #include <stdlib.h>
 #include <signal.h>
+#include <string.h>
 #include <errno.h>
 #include <unistd.h>
 #include <sys/ioctl.h>
--- a/uml_switch/port.c
+++ b/uml_switch/port.c
@@ -1,6 +1,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
+#include <string.h>
 #include <errno.h>
 #include <sys/socket.h>
 #include <sys/un.h>
--- a/uml_switch/uml_switch.c
+++ b/uml_switch/uml_switch.c
@@ -6,6 +6,7 @@
 #include <errno.h>
 #include <stdlib.h>
 #include <signal.h>
+#include <string.h>
 #include <fcntl.h>
 #include <stdint.h>
 #include <sys/socket.h>
--- a/watchdog/uml_watchdog.c
+++ b/watchdog/uml_watchdog.c
@@ -2,6 +2,7 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <signal.h>
+#include <string.h>
 #include <errno.h>
 #include <sys/socket.h>
 #include <sys/un.h>