sdk.atree does not need DIST_DIR any longer.

Change-Id: I34d8f13e1ddc27f853e3f15cfe0351d780a47aa8
diff --git a/core/Makefile b/core/Makefile
index f75f140..1d3110d 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -1399,7 +1399,6 @@
 			-I $(TARGET_COMMON_OUT_ROOT) \
 			-v "PLATFORM_NAME=android-$(PLATFORM_VERSION)" \
 			-v "OUT_DIR=$(OUT_DIR)" \
-			-v "DIST_DIR=$(DIST_DIR)" \
 			-o $(PRIVATE_DIR) && \
 		cp -f $(target_notice_file_txt) \
 				$(PRIVATE_DIR)/platforms/android-$(PLATFORM_VERSION)/images/NOTICE.txt && \