m4: use ASCII quotes `...' in man page example

The m4 syntax specifically requires `...' and not the pretty Unicode
quotes that the Sq macro can produce.  Use of escape sequences
clarified by schwarze@

diff --git a/usr.bin/m4/m4.1 b/usr.bin/m4/m4.1
index c8f9afe..58ee965 100644 (file)
--- a/usr.bin/m4/m4.1
+++ b/usr.bin/m4/m4.1
@@ -1,4 +1,4 @@
-.\"    @(#) $OpenBSD: m4.1,v 1.67 2022/06/14 15:15:17 espie Exp $
+.\"    @(#) $OpenBSD: m4.1,v 1.68 2022/06/14 21:31:45 naddy Exp $
 .\"
 .\" Copyright (c) 1989, 1993
 .\"    The Regents of the University of California.  All rights reserved.
@@ -85,7 +85,7 @@ In arguments to macros, leading unquoted space, tab, and newline
 .Pq Sq \en
 characters are ignored.
 To quote strings, use left and right single quotes
-.Pq e.g., Sq \ \&this is a string with a leading space .
+.Pq e.g., \(ga this is a string with a leading space\(aq .
 You can change the quote characters with the
 .Ic changequote
 built-in macro.