move MSG_MAXIOVLEN check out of configure.ac

configure.ac

@@ -21,9 +21,6 @@ AC_CHECK_TYPE(socklen_t, [AC_DEFINE(HAS_SOCKLEN_T)], ,
               #include <sys/socket.h>
 )
 
-AC_EGREP_HEADER(MSG_MAXIOVLEN, /usr/include/sys/socket.h, AC_DEFINE(ENET_BUFFER_MAXIMUM, [MSG_MAXIOVLEN]))
-AC_EGREP_HEADER(MSG_MAXIOVLEN, socket.h, AC_DEFINE(ENET_BUFFER_MAXIMUM, [MSG_MAXIOVLEN]))
-
 AC_CONFIG_FILES([Makefile
 	libenet.pc])
 AC_OUTPUT

include/enet/unix.h

@@ -11,6 +11,10 @@
 #include <netinet/in.h>
 #include <unistd.h>
 
+#ifdef MSG_MAXIOVLEN
+#define ENET_BUFFER_MAXIMUM MSG_MAXIOVLEN
+#endif
+
 typedef int ENetSocket;
 
 enum