argc is now used

MFC after:	2 days

usr.sbin/pkg/pkg.c

@@ -907,7 +907,7 @@ bootstrap_pkg_local(const char *pkgpath, bool force)
 }
 
 int
-main(__unused int argc, char *argv[])
+main(int argc, char *argv[])
 {
 	char pkgpath[MAXPATHLEN];
 	const char *pkgarg;