v3dv/cmd_buffer: missing (uint8_t *) casting when calling memcmp

Caused to return early wrongly on CmdPushConstants with some tests
using several calls to that method. As we are here we are also
replacing the (void *) casting at the memcpy below.

Fixes: e1c8041cde64 ("v3dv: try harder to skip emission of redundant state")

Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7718>
(cherry picked from commit ce5c23eb009b1453347e87099a4dfc72d4c8c793)
2 files changed