media: rockchip/rga: do proper error checking in probe

The latest fix for probe error handling contained a typo that causes
probing to fail with the following message:

  rockchip-rga: probe of ff680000.rga failed with error -12

This patch fixes the typo.

Fixes: e58430e (media: rockchip/rga: fix error handling in probe)
Reviewed-by: Dragan Simic <dragan.simic@gmail.com>
Signed-off-by: Kyle Copperfield <kmcopper@danwin1210.me>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

Author: Kyle Copperfield

drivers/media/platform/rockchip/rga/rga.c

@@ -892,7 +892,7 @@ static int rga_probe(struct platform_device *pdev)
 	}
 	rga->dst_mmu_pages =
 		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
-	if (rga->dst_mmu_pages) {
+	if (!rga->dst_mmu_pages) {
 		ret = -ENOMEM;
 		goto free_src_pages;
 	}