Improve module tags warnings

Stop blaming base_rules.mk, put the module makefile at the beginning
of the line. That way scripts like warn.py can parse this better.

Test: multiproduct_kati, grep logs
Change-Id: I5e6844097b44e47b8126159c1760b7524134310d
diff --git a/core/base_rules.mk b/core/base_rules.mk
index e90c1bb..f95706c 100644
--- a/core/base_rules.mk
+++ b/core/base_rules.mk
@@ -121,7 +121,7 @@
 # makefiles. Anything else is either a typo or a source of unexpected
 # behaviors.
 ifneq ($(filter-out debug eng tests optional samples,$(my_module_tags)),)
-$(warning unusual tags $(my_module_tags) on $(LOCAL_MODULE) at $(LOCAL_PATH))
+$(call pretty-warning,unusual tags $(my_module_tags))
 endif
 
 # Add implicit tags.