Fix size_t definition in x86 NDK header file

Bug: http://code.google.com/p/android/issues/detail?id=19011

The incorrect #define was being used which caused the incorrect
definition for size_t when the standalone toolchain is used.

Change-Id: Ifef4dc987c542a9c5d8bb43d84d3fe1431de9aa0
Signed-off-by: Mark D Horn <mark.d.horn@intel.com>
diff --git a/ndk/platforms/android-9/arch-x86/include/machine/_types.h b/ndk/platforms/android-9/arch-x86/include/machine/_types.h
index e9280a5..5e28c64 100644
--- a/ndk/platforms/android-9/arch-x86/include/machine/_types.h
+++ b/ndk/platforms/android-9/arch-x86/include/machine/_types.h
@@ -38,7 +38,7 @@
 /* the kernel defines size_t as unsigned int, but g++ wants it to be unsigned long */
 #ifndef _SIZE_T_DEFINED_
 #  define _SIZE_T_DEFINED_
-#  ifdef ANDROID
+#  ifdef __ANDROID__
      typedef unsigned int  size_t;
 #  else
      typedef unsigned long  size_t;