Omit multiuser.c from Windows builds.

Change-Id: I0cee35373e33084e4fc65a1d5c0b611c6fa82346
diff --git a/libcutils/Android.mk b/libcutils/Android.mk
index 9791462..78bae8a 100644
--- a/libcutils/Android.mk
+++ b/libcutils/Android.mk
@@ -51,7 +51,6 @@
 	sched_policy.c \
 	iosched_policy.c \
 	str_parms.c \
-	multiuser.c
 
 commonHostSources := \
         ashmem-host.c
@@ -79,6 +78,7 @@
         mspace.c \
         selector.c \
         tztime.c \
+        multiuser.c \
         zygote.c
 
     commonHostSources += \