Make libEGL build cleanly under 64-bit

Change-Id: I255dfb70b166b7469d59352b1acfc7aececa07de
diff --git a/opengl/libs/EGL/eglApi.cpp b/opengl/libs/EGL/eglApi.cpp
index 0cc5265..d96b54f 100644
--- a/opengl/libs/EGL/eglApi.cpp
+++ b/opengl/libs/EGL/eglApi.cpp
@@ -204,7 +204,7 @@
 {
     clearError();
 
-    uint32_t index = uint32_t(display);
+    uintptr_t index = reinterpret_cast<uintptr_t>(display);
     if (index >= NUM_DISPLAYS) {
         return setError(EGL_BAD_PARAMETER, EGL_NO_DISPLAY);
     }