Fix typo.

Change-Id: I027b91d3a89de12a9c9f95406274726574bc7f7a
diff --git a/core/base_rules.mk b/core/base_rules.mk
index 9354764..9571001 100644
--- a/core/base_rules.mk
+++ b/core/base_rules.mk
@@ -598,7 +598,7 @@
 ALL_MODULES.$(my_register_name).INSTALLED := \
     $(strip $(ALL_MODULES.$(my_register_name).INSTALLED) $(LOCAL_INSTALLED_MODULE))
 ALL_MODULES.$(my_register_name).BUILT_INSTALLED := \
-    $(strip $(ALL_MODULES.$(my_register_name).BUILT_INSTALLED)$(LOCAL_BUILT_MODULE):$(LOCAL_INSTALLED_MODULE))
+    $(strip $(ALL_MODULES.$(my_register_name).BUILT_INSTALLED) $(LOCAL_BUILT_MODULE):$(LOCAL_INSTALLED_MODULE))
 endif
 ifdef LOCAL_PICKUP_FILES
 # Files or directories ready to pick up by the build system