[PATCH -next v2] samples: vfio-mdev: fix error handing in mdpy_fb_probe()

[Wei Yongjun <weiyongjun1@xxxxxxxxxx>]

Fix to return a negative error code from the framebuffer_alloc() error
handling case instead of 0, also release regions in some error handing
cases.

Fixes: cacade1946a4 ("sample: vfio mdev display - guest driver")
Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
Signed-off-by: Wei Yongjun <weiyongjun1@xxxxxxxxxx>
---
v1 -> v2: add missing regions release.
---
 samples/vfio-mdev/mdpy-fb.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/samples/vfio-mdev/mdpy-fb.c b/samples/vfio-mdev/mdpy-fb.c
index 21dbf63d6e41..9ec93d90e8a5 100644
--- a/samples/vfio-mdev/mdpy-fb.c
+++ b/samples/vfio-mdev/mdpy-fb.c
@@ -117,22 +117,27 @@ static int mdpy_fb_probe(struct pci_dev *pdev,
 	if (format != DRM_FORMAT_XRGB8888) {
 		pci_err(pdev, "format mismatch (0x%x != 0x%x)\n",
 			format, DRM_FORMAT_XRGB8888);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto err_release_regions;
 	}
 	if (width < 100	 || width > 10000) {
 		pci_err(pdev, "width (%d) out of range\n", width);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto err_release_regions;
 	}
 	if (height < 100 || height > 10000) {
 		pci_err(pdev, "height (%d) out of range\n", height);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto err_release_regions;
 	}
 	pci_info(pdev, "mdpy found: %dx%d framebuffer\n",
 		 width, height);
 
 	info = framebuffer_alloc(sizeof(struct mdpy_fb_par), &pdev->dev);
-	if (!info)
+	if (!info) {
+		ret = -ENOMEM;
 		goto err_release_regions;
+	}
 	pci_set_drvdata(pdev, info);
 	par = info->par;