Fix CTS Builds for Mac

The cts-usb-accessory is only buildable on Linux so ignore it
when building on a Mac.

Change-Id: Ie50ada68ed4aa4513d86f4e7db8419d8f54d3271
diff --git a/apps/CtsVerifier/Android.mk b/apps/CtsVerifier/Android.mk
index 16d3de1..54fc522 100644
--- a/apps/CtsVerifier/Android.mk
+++ b/apps/CtsVerifier/Android.mk
@@ -55,11 +55,15 @@
 verifier-zip := $(cts-dir)/$(verifier-zip-name)
 
 cts : $(verifier-zip)
-$(verifier-zip) : CtsVerifier $(ACP) $(HOST_OUT)/bin/cts-usb-accessory
+ifeq ($(HOST_OS),linux)
+$(verifier-zip) : $(HOST_OUT)/bin/cts-usb-accessory
+endif
+$(verifier-zip) : $(call intermediates-dir-for,APPS,CtsVerifier)/package.apk | $(ACP)
 		$(hide) mkdir -p $(verifier-dir)
-		$(hide) $(ACP) -fp $(call intermediates-dir-for,APPS,CtsVerifier)/package.apk \
-				$(verifier-dir)/CtsVerifier.apk
+		$(hide) $(ACP) -fp $< $(verifier-dir)/CtsVerifier.apk
+ifeq ($(HOST_OS),linux)
 		$(hide) $(ACP) -fp $(HOST_OUT)/bin/cts-usb-accessory $(verifier-dir)/cts-usb-accessory
+endif
 		$(hide) cd $(cts-dir) && zip -rq $(verifier-dir-name) $(verifier-dir-name)
 
 ifneq ($(filter cts, $(MAKECMDGOALS)),)