domainname(1) - make usage __dead

[Gleydson Soares]

make usage() __dead and static, while here switch main to return instead of 
exit(3)

? domainname
Index: domainname.c
===================================================================
RCS file: /cvs/src/bin/domainname/domainname.c,v
retrieving revision 1.9
diff -u -p -r1.9 domainname.c
--- domainname.c        16 Jan 2015 06:39:31 -0000      1.9
+++ domainname.c        29 Jan 2016 18:06:46 -0000
@@ -39,7 +39,7 @@
 
 extern char *__progname;
 
-void usage(void);
+__dead static void usage(void);
 
 int
 main(int argc, char *argv[])
@@ -66,10 +66,10 @@ main(int argc, char *argv[])
                        err(1, "getdomainname");
                (void)printf("%s\n", domainname);
        }
-       exit(0);
+       return(0);
 }
 
-void
+__dead static void
 usage(void)
 {
        (void)fprintf(stderr, "usage: %s [name-of-domain]\n", __progname);