Revert to check the Poppler::Sound, otherwise the most of the Poppler API won't match.

I'll temporary patch okular until Poppler 0.6 final.

CCMAIL: bradh@frogmouth.net

svn path=/trunk/KDE/kdegraphics/cmake/modules/; revision=693749

cmake/modules/FindPoppler.cmake

@@ -53,8 +53,8 @@ check_cxx_source_compiles("
 
 int main()
 {
-  Poppler::Document *doc = Poppler::Document::load(QString());
-  doc->embeddedFiles().at(0)->checksum();
+  Poppler::SoundObject * so = 0;
+  (void)so;
 
   return 0;
 }