cifs: writing past end of struct in cifs_convert_address()

"s6->sin6_scope_id" is an int bits but strict_strtoul() writes a long
so this can corrupt memory on 64 bit systems.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

fs/cifs/netmisc.c

@@ -197,8 +197,7 @@ cifs_convert_address(struct sockaddr *dst, const char *src, int len)
 		memcpy(scope_id, pct + 1, slen);
 		scope_id[slen] = '\0';
 
-		rc = strict_strtoul(scope_id, 0,
-					(unsigned long *)&s6->sin6_scope_id);
+		rc = kstrtouint(scope_id, 0, &s6->sin6_scope_id);
 		rc = (rc == 0) ? 1 : 0;
 	}