missing_socket: drop unnecessary definitions

Now, we have copy of vm_sockets.h, hence these definitions are not
necessary anymore.

src/basic/missing_socket.h

@@ -3,42 +3,6 @@
 
 #include <sys/socket.h>
 
-#if HAVE_LINUX_VM_SOCKETS_H
-#include <linux/vm_sockets.h>
-#else
-struct sockaddr_vm {
-        unsigned short svm_family;
-        unsigned short svm_reserved1;
-        unsigned int svm_port;
-        unsigned int svm_cid;
-        unsigned char svm_zero[sizeof(struct sockaddr) -
-                               sizeof(unsigned short) -
-                               sizeof(unsigned short) -
-                               sizeof(unsigned int) -
-                               sizeof(unsigned int)];
-};
-#endif /* !HAVE_LINUX_VM_SOCKETS_H */
-
-#ifndef VMADDR_CID_ANY
-#define VMADDR_CID_ANY -1U
-#endif
-
-#ifndef VMADDR_CID_HYPERVISOR
-#define VMADDR_CID_HYPERVISOR 0U
-#endif
-
-#ifndef VMADDR_CID_LOCAL
-#define VMADDR_CID_LOCAL 1U
-#endif
-
-#ifndef VMADDR_CID_HOST
-#define VMADDR_CID_HOST 2U
-#endif
-
-#ifndef VMADDR_PORT_ANY
-#define VMADDR_PORT_ANY -1U
-#endif
-
 #ifndef AF_VSOCK
 #define AF_VSOCK 40
 #endif
@@ -104,8 +68,3 @@ struct sockaddr_vm {
 #ifndef IPV6_RECVFRAGSIZE
 #define IPV6_RECVFRAGSIZE 77
 #endif
-
-/* linux/sockios.h */
-#ifndef SIOCGSKNS
-#define SIOCGSKNS 0x894C
-#endif