fix return value for render_pictures

Review URL: https://codereview.appspot.com/6590049

git-svn-id: http://skia.googlecode.com/svn/trunk@5779 2bbb7eff-a529-9590-31e7-b0007b416f81

tools/bench_pictures_main.cpp

@@ -466,6 +466,7 @@ int tool_main(int argc, char** argv) {
         gLogger.logError(err);
         return 1;
     }
+    return 0;
 }
 
 #if !defined SK_BUILD_FOR_IOS

tools/render_pictures_main.cpp

@@ -316,6 +316,7 @@ int tool_main(int argc, char** argv) {
 #endif
 
     SkDELETE(renderer);
+    return 0;
 }
 
 #if !defined SK_BUILD_FOR_IOS