Rename CONFIG_MEMCHECK to CONFIG_ANDROID_MEMCHECK

Change-Id: I9b0edcc1e243111f86f18c22eecbebb23219c297
diff --git a/exec.c b/exec.c
index f07d0db..d34c8e8 100644
--- a/exec.c
+++ b/exec.c
@@ -47,9 +47,9 @@
 #if defined(CONFIG_USER_ONLY)
 #include <qemu.h>
 #endif
-#ifdef CONFIG_MEMCHECK
+#ifdef CONFIG_ANDROID_MEMCHECK
 #include "android/qemu/memcheck/memcheck_api.h"
-#endif  // CONFIG_MEMCHECK
+#endif  // CONFIG_ANDROID_MEMCHECK
 
 //#define DEBUG_SUBPAGE