Don't set platform to linux2

* Per python 3.3 changes PLATFORM shouldn't contain major verion

Change-Id: I8e2e7db5a114c054f5b5ab93009508db29c2debf
diff --git a/Android.bp b/Android.bp
index 7449c17..0e41bf4 100644
--- a/Android.bp
+++ b/Android.bp
@@ -221,7 +221,7 @@
     target: {
         linux: {
             cflags: [
-                "-DPLATFORM=\"linux2\"",
+                "-DPLATFORM=\"linux\"",
             ],
         },
         darwin_x86_64: {