sock_diag: Move the SOCK_DIAG_BY_FAMILY cmd declaration

It should belong to sock_diag, not inet_diag.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/inet_diag.h

@@ -6,7 +6,6 @@
 /* Just some random number */
 #define TCPDIAG_GETSOCK 18
 #define DCCPDIAG_GETSOCK 19
-#define SOCK_DIAG_BY_FAMILY 20
 
 #define INET_DIAG_GETSOCK_MAX 24
 

include/linux/sock_diag.h

 #ifndef __SOCK_DIAG_H__
 #define __SOCK_DIAG_H__
+
+#define SOCK_DIAG_BY_FAMILY 20
+
 struct sk_buff;
 struct nlmsghdr;