tcm_loop: Check for valid hba in tcm_loop_drop_nexus()

Signed-off-by: Hannes Reinecke <[e-mail]>
Signed-off-by: Nicholas Bellinger <[e-mail]>

drivers/target/loopback/tcm_loop.c

···
 	struct tcm_loop_nexus *tl_nexus;
 	struct tcm_loop_hba *tl_hba = tpg->tl_hba;
 
-	tl_nexus = tpg->tl_hba->tl_nexus;
+	if (!tl_hba)
+		return -ENODEV;
+
+	tl_nexus = tl_hba->tl_nexus;
 	if (!tl_nexus)
 		return -ENODEV;