drm/vmwgfx: replace idr_init() by idr_init_base()

idr_init() uses base 0 which is an invalid identifier for this driver.
The idr_alloc for this driver uses 1 as start value for ID range. The
new function idr_init_base allows IDR to set the ID lookup from base 1.
This avoids all lookups that otherwise starts from 0 since 0 is always
unused / available.

References: commit 6ce711f2 ("idr: Make 1-based IDRs more efficient")
Signed-off-by: Deepak R Varma <mh12gx2825@gmail.com>
Signed-off-by: Zack Rusin <zackr@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201105190718.GA89863@localhost

drivers/gpu/drm/vmwgfx/ttm_object.c

@@ -540,7 +540,7 @@ ttm_object_device_init(struct ttm_mem_global *mem_glob,
 	if (ret != 0)
 		goto out_no_object_hash;
 
-	idr_init(&tdev->idr);
+	idr_init_base(&tdev->idr, 1);
 	tdev->ops = *ops;
 	tdev->dmabuf_release = tdev->ops.release;
 	tdev->ops.release = ttm_prime_dmabuf_release;

drivers/gpu/drm/vmwgfx/vmwgfx_drv.c

@@ -725,7 +725,7 @@ static int vmw_driver_load(struct vmw_private *dev_priv, u32 pci_id)
 	spin_lock_init(&dev_priv->cursor_lock);
 
 	for (i = vmw_res_context; i < vmw_res_max; ++i) {
-		idr_init(&dev_priv->res_idr[i]);
+		idr_init_base(&dev_priv->res_idr[i], 1);
 		INIT_LIST_HEAD(&dev_priv->res_lru[i]);
 	}