[gtk-doc] tests: fix the new diff test

[Stefan Kost <stefkost src gnome org>]

commit 78f59c3db5bf99d0bc81e88d8e16eb969cf87edb
Author: Stefan Sauer <ensonic users sf net>
Date:   Sun May 17 10:17:36 2015 +0200

    tests: fix the new diff test
    
    The path was wrong. Also don't break on first error and output in unified diff format.

 tests/sanity.sh |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/tests/sanity.sh b/tests/sanity.sh
index 81f417f..faa2aa8 100755
--- a/tests/sanity.sh
+++ b/tests/sanity.sh
@@ -92,12 +92,12 @@ tested=`expr $tested + 1`
 
 # check stability of generated html
 nok=0
-for path in $dir/*/docs*/html; do
+for path in $dir/*/docs*; do
   if test -d $path/html.ref; then
-    diff $path/html.ref $path/html
+    diff -u $path/html.ref $path/html
     if test $? = 1 ; then
       echo 1>&2 "difference in generated html for $path"
-      nok=`expr $nok + 1`; break;
+      nok=`expr $nok + 1`;
     fi
   fi
 done