Use unmodified MAKECMDGOALS in ninja.mk.

The build system removes targets like "PRODUCT-full-eng" from
MAKECMDGOALS in build/core/product_config.mk.
Without this change, such target isn't passed to kati.

Change-Id: I0b3949ed1f5557445d7f5d5bd59b7875c0b2ea7f
diff --git a/core/main.mk b/core/main.mk
index 38fe994..b290ce1 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -86,6 +86,8 @@
 dont_bother := true
 endif
 
+ORIGINAL_MAKECMDGOALS := $(MAKECMDGOALS)
+
 # Targets that provide quick help on the build system.
 include $(BUILD_SYSTEM)/help.mk