linux: include sys/socket.h in linux/vm_sockets.h

The header requires struct sockaddr declared. So, otherwise, we need to
include sys/socket.h earlier than linux/vm_sockets.h.
Let's make the header includable at any place.

src/basic/include/linux/update.sh

@@ -29,5 +29,9 @@ for i in *.h */*.h; do
             # add casts in ethtool_cmd_speed()
             sed -r -i '/return (ep->speed_hi << 16) | ep->speed;/ s/return .*;/return ((__u32) ep->speed_hi << 16) | (__u32) ep->speed;/' "$i"
             ;;
+        vm_sockets.h)
+            # the header requires struct sockaddr declared
+            sed -r -i '/#define _VM_SOCKETS_H/a \\n#include <sys/socket.h>' "$i"
+            ;;
     esac
 done

src/basic/include/linux/vm_sockets.h

@@ -17,6 +17,8 @@
 #ifndef _VM_SOCKETS_H
 #define _VM_SOCKETS_H
 
+#include <sys/socket.h>
+
 #include <linux/socket.h>
 #include <linux/types.h>