softpipe: correct signature of get_compiler_options

This gets rid of a harmless but annoying compiler warning on MSVC.

Fixes: 73bafb5ee38 ("gallium: s/unsigned/enum pipe_shader_type/ for get_compiler_options()")
Reviewed-By: Mike Blumenkrantz <michael.blumenkrantz@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7524>
(cherry picked from commit 7a1346b26a70a9d6000f4889ab4d594a6a445d6d)
2 files changed