wiener_lpdf parameter order

[CarlyLasagna]

There are some inconsistencies in the ordering of the parameters in the wiener_lpdf code (see lines 109, 115, 121-122): https://github.com/stan-dev/math/blob/3a080d74172c19f7eb9e7339214bcc4e2847c3bb/stan/math/prim/prob/wiener_lpdf.hpp

It's unclear (and probably unlikely) that this affects the functionality, but is worth noting. In general, the parameters are presented in this order: alpha, tau, beta, delta. But in some cases they are presented in a different order (alpha, beta, tau, delta; see lines 109, 115, 121-122). Ideally the former order should be preserved throughout the code.

[rok-cesnovar]

This definitely does not affect the functionality, but could be something to address if it would improve readability.

[CarlyLasagna]

Thanks for the quick reply. Definitely would improve readability. I figured as much about the functionality.