For IPv6 the userspace mount helper sends an address in the "ip="
option. This check fails if the length is > 35 characters. I have no
idea where the magic 35 character limit came from, but it's clearly not
enough for IPv6. Fix it by making it use the INET6_ADDRSTRLEN #define.
While we're at it, use the same #define for the address length in SPNEGO
upcalls.
Reported-by: Charles R. Anderson <cra@wpi.edu> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <sfrench@us.ibm.com>