xfs: fix uninitialized list head in struct xfs_refcount_recovery

We're supposed to initialize the list head of an object before adding it
to another list.  Fix that, and stop using the kmem_{alloc,free} calls
from the Irix days.

Fixes: 174edb0e ("xfs: store in-progress CoW allocations in the refcount btree")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

fs/xfs/libxfs/xfs_refcount.c

@@ -1767,12 +1767,14 @@ xfs_refcount_recover_extent(
 			   be32_to_cpu(rec->refc.rc_refcount) != 1))
 		return -EFSCORRUPTED;
 
-	rr = kmem_alloc(sizeof(struct xfs_refcount_recovery), 0);
+	rr = kmalloc(sizeof(struct xfs_refcount_recovery),
+			GFP_KERNEL | __GFP_NOFAIL);
+	INIT_LIST_HEAD(&rr->rr_list);
 	xfs_refcount_btrec_to_irec(rec, &rr->rr_rrec);
 
 	if (XFS_IS_CORRUPT(cur->bc_mp,
 			   rr->rr_rrec.rc_domain != XFS_REFC_DOMAIN_COW)) {
-		kmem_free(rr);
+		kfree(rr);
 		return -EFSCORRUPTED;
 	}
 
@@ -1859,7 +1861,7 @@ xfs_refcount_recover_cow_leftovers(
 			goto out_free;
 
 		list_del(&rr->rr_list);
-		kmem_free(rr);
+		kfree(rr);
 	}
 
 	return error;
@@ -1869,7 +1871,7 @@ xfs_refcount_recover_cow_leftovers(
 	/* Free the leftover list */
 	list_for_each_entry_safe(rr, n, &debris, rr_list) {
 		list_del(&rr->rr_list);
-		kmem_free(rr);
+		kfree(rr);
 	}
 	return error;
 }