Fixes running vncserver on beagleboard/0xdroid and possibly any device

without a touch screen. Because fake touch screen always report
zero when query device information, coordinates transformation is not
needed.

Signed-off-by: Christian Beier <dontmind@freeshell.org>

examples/android/jni/fbvncserver.c

@@ -309,8 +309,12 @@ void injectTouchEvent(int down, int x, int y)
     struct input_event ev;
     
     // Calculate the final x and y
-    x = xmin + (x * (xmax - xmin)) / (scrinfo.xres);
-    y = ymin + (y * (ymax - ymin)) / (scrinfo.yres);
+    /* Fake touch screen always reports zero */
+    if (xmin != 0 && xmax != 0 && ymin != 0 && ymax != 0)
+    {
+        x = xmin + (x * (xmax - xmin)) / (scrinfo.xres);
+        y = ymin + (y * (ymax - ymin)) / (scrinfo.yres);
+    }
     
     memset(&ev, 0, sizeof(ev));