Initialize reference counter for egl_display_t

Add missing member initialization for reference counter, used to determine
if a context is ready.

Change-Id: I45f81177ac2851129681f827afe015b60b3cd73c
diff --git a/opengl/libs/EGL/egl.cpp b/opengl/libs/EGL/egl.cpp
index a53b375..6474c87 100644
--- a/opengl/libs/EGL/egl.cpp
+++ b/opengl/libs/EGL/egl.cpp
@@ -120,7 +120,7 @@
 
     SortedVector<egl_object_t*> objects;
 
-    egl_display_t() : magic('_dpy'), numTotalConfigs(0), configs(0) { }
+    egl_display_t() : magic('_dpy'), numTotalConfigs(0), configs(0), refs(0) { }
     ~egl_display_t() { magic = 0; }
     inline bool isReady() const { return (refs > 0); }
     inline bool isValid() const { return magic == '_dpy'; }