target: Use array_zalloc for device_list

Turns an order-8 allocation into slab-sized ones, thereby preventing
allocation failures with memory fragmentation.

This likely saves memory as well, as the slab allocator can pack objects
more tightly than the buddy allocator.

(nab: Fix lio-core patch fuzz)

Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index fc918a7..aaccc5f 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -629,7 +629,7 @@
 	spinlock_t		stats_lock;
 	/* Used for PR SPEC_I_PT=1 and REGISTER_AND_MOVE */
 	atomic_t		acl_pr_ref_count;
-	struct se_dev_entry	*device_list;
+	struct se_dev_entry	**device_list;
 	struct se_session	*nacl_sess;
 	struct se_portal_group *se_tpg;
 	spinlock_t		device_list_lock;