Re-enable FAST_TLS in gl2 code

Temporarily changed USE_FAST_TLS_KEY ifdef during debugging. Changing it
back now.

Change-Id: I7c2fcf7265b3d545e31ff7683bd7614100fad3e5
diff --git a/opengl/libs/GLES2/gl2.cpp b/opengl/libs/GLES2/gl2.cpp
index 9e52298..2d0045e 100644
--- a/opengl/libs/GLES2/gl2.cpp
+++ b/opengl/libs/GLES2/gl2.cpp
@@ -48,7 +48,7 @@
 #define DEBUG_PRINT_CALL_STACK_ON_ERROR 0
 #define SYSTRACE_CALL_GL_API 0
 
-#if USE_FAST_TLS_KEY___
+#if USE_FAST_TLS_KEY
 
     #ifdef HAVE_ARM_TLS_REGISTER
         #define GET_TLS(reg) \