Revert "niu: fix missing checks of niu_pci_eeprom_read"

stable inclusion
from linux-4.19.192
commit 8432db9d8a34f26030cee45e64a56a2e033d3ba6

--------------------------------

commit 7930742d upstream.

This reverts commit 26fd962b.

Because of recent interactions with developers from @umn.edu, all
commits from them have been recently re-reviewed to ensure if they were
correct or not.

Upon review, this commit was found to be incorrect for the reasons
below, so it must be reverted.  It will be fixed up "correctly" in a
later kernel change.

The change here was incorrect.  While it is nice to check if
niu_pci_eeprom_read() succeeded or not when using the data, any error
that might have happened was not propagated upwards properly, causing
the kernel to assume that these reads were successful, which results in
invalid data in the buffer that was to contain the successfully read
data.

Cc: Kangjie Lu <kjlu@umn.edu>
Cc: Shannon Nelson <shannon.lee.nelson@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Fixes: 26fd962b ("niu: fix missing checks of niu_pci_eeprom_read")
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210503115736.2104747-23-gregkh@linuxfoundation.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/net/ethernet/sun/niu.c

@@ -8100,8 +8100,6 @@ static int niu_pci_vpd_scan_props(struct niu *np, u32 start, u32 end)
 		start += 3;
 
 		prop_len = niu_pci_eeprom_read(np, start + 4);
-		if (prop_len < 0)
-			return prop_len;
 		err = niu_pci_vpd_get_propname(np, start + 5, namebuf, 64);
 		if (err < 0)
 			return err;
@@ -8146,12 +8144,8 @@ static int niu_pci_vpd_scan_props(struct niu *np, u32 start, u32 end)
 			netif_printk(np, probe, KERN_DEBUG, np->dev,
 				     "VPD_SCAN: Reading in property [%s] len[%d]\n",
 				     namebuf, prop_len);
-			for (i = 0; i < prop_len; i++) {
-				err = niu_pci_eeprom_read(np, off + i);
-				if (err >= 0)
-					*prop_buf = err;
-				++prop_buf;
-			}
+			for (i = 0; i < prop_len; i++)
+				*prop_buf++ = niu_pci_eeprom_read(np, off + i);
 		}
 
 		start += len;