httpd(8) fix incorrect comment

[Frank Schoep]

Came across an incorrect comment in httpd(8) explaining memory
allocation. Comment claims that 5 times the source memory needs to
be allocated if source consists solely of "<" and ">", but those
characters expand to four bytes ("&[g/l]t;"). "&" is the reason that
5 times the memory is required ("&amp;");


Index: httpd.c
===================================================================
RCS file: /cvs/src/usr.sbin/httpd/httpd.c,v
retrieving revision 1.55
diff -u -p -r1.55 httpd.c
--- httpd.c     22 May 2016 19:19:21 -0000      1.55
+++ httpd.c     7 Jun 2016 09:18:47 -0000
@@ -744,7 +744,10 @@ escape_html(const char* src)
{
        char            *dp, *dst;

-       /* We need 5 times the memory if every letter is "<" or ">". */
+       /*
+        * We need 5 times the memory if every source character is
+        * "&" (escaped to "&amp;").
+        */
        if ((dst = calloc(5, strlen(src) + 1)) == NULL)
                return NULL;