libndr: Return error code from ndr_token_peek()

libndr: Return error code from ndr_token_peek()

This makes it safer to change our code to remove tokens after use
if failing to obtain a token would result in an error.

This means changing ndr_get_array_size() and ndr_get_array_length()
to also return an error code.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14710

Signed-off-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>