include/uapi/linux/if_pppox.h: include linux/in.h and linux/in6.h

Fixes userspace compilation errors:

error: field ‘addr’ has incomplete type
 struct sockaddr_in addr; /* IP address and port to send to */

error: field ‘addr’ has incomplete type
 struct sockaddr_in6 addr; /* IP address and port to send to */

Signed-off-by: Mikko Rapeli <mikko.rapeli@iki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/if_pppox.h

@@ -24,6 +24,8 @@
 #include <linux/if.h>
 #include <linux/if_ether.h>
 #include <linux/if_pppol2tp.h>
+#include <linux/in.h>
+#include <linux/in6.h>
 
 /* For user-space programs to pick up these definitions
  * which they wouldn't get otherwise without defining __KERNEL__