nir: remove old assert

nir: remove old assert

This was originally intended to make sure the remap location
was not -1. However the code has changed alot since then,
the location is now never set to -1 and we also handle
components meaning this old assert has been doing comparisions
with the pointer to the array of component data.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105183