mesa/main: fix meta caller of _mesa_ClampColor

mesa/main: fix meta caller of _mesa_ClampColor

Since _mesa_ClampColor properly checks for support of the API function
now, it's meta callers need to check support as well.

Fixes: 963311b71f ("mesa/main: fix version/extension checks in _mesa_ClampColor")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99401
Tested-by: Mark Janes <mark.a.janes@intel.com>
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Cc: "17.0" <mesa-stable@lists.freedesktop.org>
(cherry picked from commit a7c635ec6589f600f0d52d0097774ea0b938de9f)