pan/midgard: Use a signed value for checking inline constants

Inline constants are sign extended, so we should use a int16_t instead
of an unsigned type.

Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5351>
2 files changed