tools/xenstored: Remove stubdom special casing

posix.c and minios.c implement the same named functions serving slightly
different purposes.

For xenbus_map()
posix.c maps the local /dev/xen/xsd_kva
minios.c maps dom0 via grant and there is open coding for stub_domid in
map_interface.

Change xenbus_map() to map the local domain's interface.  The default
grant table mapping is performed otherwise.

Signed-off-by: Jason Andryuk <jason.andryuk@amd.com>
Reviewed-by: Juergen Gross <jgross@suse.com>

tools/xenstored/domain.c

@@ -512,11 +512,6 @@ static void *map_interface(domid_t domid)
 	if (domid == store_domid)
 		return xenbus_map();
 
-#ifdef __MINIOS__
-	if (domid == stub_domid)
-		return xenstore_buf;
-#endif
-
 	return xengnttab_map_grant_ref(*xgt_handle, domid,
 				       GNTTAB_RESERVED_XENSTORE,
 				       PROT_READ|PROT_WRITE);

tools/xenstored/minios.c

@@ -61,13 +61,11 @@ evtchn_port_t get_domain_evtchn(unsigned int domid)
 
 void *xenbus_map(void)
 {
-	return xengnttab_map_grant_ref(*xgt_handle, xenbus_master_domid(),
-			GNTTAB_RESERVED_XENSTORE, PROT_READ|PROT_WRITE);
+	return xenstore_buf;
 }
 
 void unmap_xenbus(void *interface)
 {
-	xengnttab_unmap(*xgt_handle, interface, 1);
 }
 
 void early_init(bool live_update, bool dofork, const char *pidfile)