Add missing include, noted by Larry Doolittle.

libbb/xgethostbyname.c

@@ -24,6 +24,8 @@
 #include <netdb.h>
 extern int h_errno;
 
+#include "libbb.h"
+
 struct hostent *xgethostbyname(const char *name)
 {
 	struct hostent *retval;