staging: rtl8723bs: Fix an error handling path

'ret' is known to be 0 at this point. It must be set to -ENOMEM if a
memory allocation occurs.

Fixes: 554c0a3a ("staging: Add rtl8723bs sdio wifi driver")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/a9533d1594900152e1e64e9f09e54240e3b7062a.1624177169.git.christophe.jaillet@wanadoo.frSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8723bs/os_dep/ioctl_linux.c

@@ -420,8 +420,10 @@ static int wpa_set_encryption(struct net_device *dev, struct ieee_param *param,
 			wep_key_len = wep_key_len <= 5 ? 5 : 13;
 			wep_total_len = wep_key_len + FIELD_OFFSET(struct ndis_802_11_wep, KeyMaterial);
 			pwep = kzalloc(wep_total_len, GFP_KERNEL);
-			if (!pwep)
+			if (!pwep) {
+				ret = -ENOMEM;
 				goto exit;
+			}
 
 			pwep->KeyLength = wep_key_len;
 			pwep->Length = wep_total_len;