mboxd: Rename windows files

Change-Id: I44e110906fd0f751f8f34b175f971e65896a7301
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
diff --git a/Makefile.am b/Makefile.am
index dd3fcc1..5e12147 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -9,7 +9,7 @@
 	control_dbus.c \
 	lpc.c \
 	mboxd_msg.c \
-	mboxd_windows.c \
+	windows.c \
 	mtd.c
 mboxd_LDFLAGS = $(LIBSYSTEMD_LIBS)
 mboxd_CFLAGS = $(LIBSYSTEMD_CFLAGS)