Fix compilation error on newer linux versions

Taken from https://lkml.org/lkml/2019/6/3/988

Author: spycrab

linux-user/syscall.c

@@ -40,6 +40,7 @@
 #include <sys/resource.h>
 #include <sys/swap.h>
 #include <linux/capability.h>
+#include <linux/sockios.h>
 #include <sched.h>
 #include <sys/timex.h>
 #include <sys/socket.h>