drm/lima: fix a memleak in lima_heap_alloc

When lima_vm_map_bo fails, the resources need to be deallocated, or
there will be memleaks.

Fixes: 6aebc51 ("drm/lima: support heap buffer creation")
Signed-off-by: Zhipeng Lu <alexious@zju.edu.cn>
Signed-off-by: Qiang Yu <yuq825@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240117071328.3811480-1-alexious@zju.edu.cn

drivers/gpu/drm/lima/lima_gem.c

@@ -75,29 +75,34 @@ int lima_heap_alloc(struct lima_bo *bo, struct lima_vm *vm)
 	} else {
 		bo->base.sgt = kmalloc(sizeof(*bo->base.sgt), GFP_KERNEL);
 		if (!bo->base.sgt) {
-			sg_free_table(&sgt);
-			return -ENOMEM;
+			ret = -ENOMEM;
+			goto err_out0;
 		}
 	}
 
 	ret = dma_map_sgtable(dev, &sgt, DMA_BIDIRECTIONAL, 0);
-	if (ret) {
-		sg_free_table(&sgt);
-		kfree(bo->base.sgt);
-		bo->base.sgt = NULL;
-		return ret;
-	}
+	if (ret)
+		goto err_out1;
 
 	*bo->base.sgt = sgt;
 
 	if (vm) {
 		ret = lima_vm_map_bo(vm, bo, old_size >> PAGE_SHIFT);
 		if (ret)
-			return ret;
+			goto err_out2;
 	}
 
 	bo->heap_size = new_size;
 	return 0;
+
+err_out2:
+	dma_unmap_sgtable(dev, &sgt, DMA_BIDIRECTIONAL, 0);
+err_out1:
+	kfree(bo->base.sgt);
+	bo->base.sgt = NULL;
+err_out0:
+	sg_free_table(&sgt);
+	return ret;
 }
 
 int lima_gem_create_handle(struct drm_device *dev, struct drm_file *file,