Fixed a compile warning treated as an error on psp - switched an int loop var to size_t.

projects/mtg/src/TextScroller.cpp

@@ -64,7 +64,7 @@ void TextScroller::Update(float dt){
     ostringstream scrollerText;
     if ( timer == 0 )
     {
-      for ( int idx = 0; idx < (MIN(2, strings.size())); idx ++ )
+      for ( size_t idx = 0; idx < (MIN(2, strings.size())); idx ++ )
       {
         scrollerText << strings[currentId + idx];
       }