Fix build caused by 168380

Change-Id: Iebda5669f48fe505146b8f2f8b35d06621d4b0e6
diff --git a/core/main.mk b/core/main.mk
index 41e788f..5604df2 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -213,7 +213,7 @@
 # pdk2 : HAL build for chipset vendors
 
 PDK_BUILD_TYPE:= $(filter pdk1 pdk2,$(MAKECMDGOALS))
-ifneq (1,$(words $(PDK_BUILD_TYPE)))
+ifeq (2,$(words $(PDK_BUILD_TYPE)))
   $(error You can't build pdk1 and pdk2 in the same run.)
 endif
 ifneq ($(PDK_BUILD_TYPE),)