[yelp-tools] Fix posix shell syntax error

[Shaun McCance <shaunm src gnome org>]

commit e414c6afd3f2e20992ad489b07ea512dadd31f81
Author: Michael Biebl <biebl debian org>
Date:   Thu Oct 17 00:18:44 2013 +0200

    Fix posix shell syntax error
    
    https://bugzilla.gnome.org/show_bug.cgi?id=710331

 tools/yelp-check.in |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/tools/yelp-check.in b/tools/yelp-check.in
index a5baa24..1ad0c20 100755
--- a/tools/yelp-check.in
+++ b/tools/yelp-check.in
@@ -275,7 +275,8 @@ yelp_hrefs () {
 }
 
 yelp_ids_page () {
-    pageid=$((
+    pageid=$(
+    (
         echo '<xsl:stylesheet'
         echo ' xmlns:xsl="http://www.w3.org/1999/XSL/Transform";'
         echo ' xmlns:mal="http://projectmallard.org/1.0/";'