The code finds, the '%' sign in an ipv6 address and copies that to a
buffer allocated on the stack. It then ignores that buffer, and passes
'pct' to simple_strtoul(), which doesn't work right because we're
comparing 'endp' against a completely different string.

Fix it by passing the correct pointer. While we're at it, this is a
good candidate for conversion to strict_strtoul as well.

Cc: stable@kernel.org
Cc: David Howells <dhowells@redhat.com>
Reported-by: NBjörn JACKE <bj@sernet.de>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>