r600/sfn: Use correct setter method.
Fix warning reported by Coverity Scan. Useless call (USELESS_CALL) side_effect_free: Calling v->pin_to_channel() is only useful for its return value, which is ignored. Fixes: 5d10e3ec ("r600/nir: Pin interpolation results to channel") Signed-off-by:Vinson Lee <vlee@freedesktop.org> Reviewed-by:
Gert Wollny <gert.wollny@collabora.com> Part-of: <mesa/mesa!5197> (cherry picked from commit 1241f8cb)