pmccabe2html: fix gawk regex escaping

* build-aux/pmccabe2html: Add one more backslash to properly
escape the gsub replacement value.  Fixes this error:
gawk: ./build-aux/pmccabe2html:425: \
warning: escape sequence `\&' treated as plain `&'

1 files changed, 3 insertions, 3 deletions

diff --git a/build-aux/pmccabe2html b/build-aux/pmccabe2html
index 18984321f8..ef54eccba5 100644
--- a/build-aux/pmccabe2html
+++ b/build-aux/pmccabe2html
@@ -422,9 +422,9 @@ function html_fnc (nfun,
 
             while ((getline codeline < (fname nfun "_fn.txt")) > 0)
             {
-                gsub(/&/, "\&amp;", codeline)	# Must come first.
-                gsub(/</, "\&lt;", codeline)
-                gsub(/>/, "\&gt;", codeline)
+                gsub(/&/, "\\&amp;", codeline)	# Must come first.
+                gsub(/</, "\\&lt;", codeline)
+                gsub(/>/, "\\&gt;", codeline)
 
                 print codeline
             }