Fix the Chrome app crash in emulator issue

The TLS desctuctor callback function eglReleaseThread needs to
access EGLThreadInfo but it has been released by tlsDestruct.
That causes the crash issue when Chrome app is opened.
Change the EGLThreadInfo pointer value to NULL just after
EGLThreadInfo object is released, can fix the problem.

Change-Id: I7cdc7bdcd602af00369e570b0d2be168b76143a6
Signed-off-by: Tina Zhang <tina.zhang@intel.com>
diff --git a/opengl/system/OpenglSystemCommon/ThreadInfo.cpp b/opengl/system/OpenglSystemCommon/ThreadInfo.cpp
index 75da8f2..f9c8521 100644
--- a/opengl/system/OpenglSystemCommon/ThreadInfo.cpp
+++ b/opengl/system/OpenglSystemCommon/ThreadInfo.cpp
@@ -24,6 +24,7 @@
         EGLThreadInfo *ti = (EGLThreadInfo *)ptr;
         delete ti->hostConn;
         delete ti;
+        ((intptr_t *)__get_tls())[TLS_SLOT_OPENGL] = NULL;
     }
 }