xen/tmem: use BUILD_BUG_ON() in favor of BUG_ON()

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
diff --git a/drivers/xen/tmem.c b/drivers/xen/tmem.c
index c4211a3..c87fdee 100644
--- a/drivers/xen/tmem.c
+++ b/drivers/xen/tmem.c
@@ -395,7 +395,7 @@
 	}
 #endif
 #ifdef CONFIG_CLEANCACHE
-	BUG_ON(sizeof(struct cleancache_filekey) != sizeof(struct tmem_oid));
+	BUILD_BUG_ON(sizeof(struct cleancache_filekey) != sizeof(struct tmem_oid));
 	if (tmem_enabled && cleancache) {
 		int err;