build fails due to intrctl on ARM

[Rin Okuyama <rokuyama%rk.phys.keio.ac.jp@localhost>]

Build fails due to intrctl(8) on ARM, whose char is unsigned. Please
apply the attached patch.

Thanks,
Rin
====
--- src/usr.sbin/intrctl/intrctl.c.orig	2016-10-16 05:31:55.270511416 +0900
+++ src/usr.sbin/intrctl/intrctl.c	2016-10-16 05:32:14.437245115 +0900
@@ -118,7 +118,7 @@
 	void *handle;
 	size_t intridlen;
 	int compact = 0;
-	char ch;
+	int ch;
 
 	while ((ch = getopt(argc, argv, "c")) != -1) {
 		switch (ch) {