Convert REINPLACE_CMD to patch file

sysutils/agedu/Makefile

@@ -18,7 +18,4 @@ GNU_CONFIGURE=	yes
 PLIST_FILES=	bin/agedu \
 		man/man1/agedu.1.gz
 
-post-patch:
-	@${REINPLACE_CMD} -e 's|HOST_NAME_MAX|_POSIX_&|' ${WRKSRC}/httpd.c
-
 .include <bsd.port.mk>

sysutils/agedu/files/patch-httpd.c

@@ -0,0 +1,11 @@
+--- httpd.c.orig	2020-07-05 01:20:14 UTC
++++ httpd.c
+@@ -570,7 +570,7 @@ static int make_listening_sockets(struct listenfds *fd
+         portstr = NULL;                /* normalise NULL and empty string */
+ 
+     if (!address) {
+-        char hostname[HOST_NAME_MAX];
++        char hostname[_POSIX_HOST_NAME_MAX];
+         if (gethostname(hostname, sizeof(hostname)) < 0) {
+             perror("hostname");
+             return -1;