swscale-example: Don't return random value from main().

Originally committed as revision 29504 to svn://svn.mplayerhq.hu/mplayer/trunk/libswscale

libswscale/swscale-example.c

@@ -233,5 +233,5 @@ int main(int argc, char **argv){
 
     selfTest(src, stride, W, H);
 
-    return 123;
+    return 0;
 }