Fixed an incorrect return value.

TRAC #22149

git-svn-id: https://angleproject.googlecode.com/svn/branches/dx11proto@1522 736b8ea6-26fd-11df-bfd4-992fa37f6226
diff --git a/src/libGLESv2/renderer/Renderer11.cpp b/src/libGLESv2/renderer/Renderer11.cpp
index 6982a41..57cc3c8 100644
--- a/src/libGLESv2/renderer/Renderer11.cpp
+++ b/src/libGLESv2/renderer/Renderer11.cpp
@@ -454,7 +454,7 @@
         if (!renderbufferObject)
         {
             ERR("render target pointer unexpectedly null.");
-            return;
+            return false;
         }
 
         renderTargetSerial = renderbufferObject->getSerial();