nv50/ir: fix wrong check when optimizing MAD to SHLADD

Checking if MAD is supported is definitely wrong, and it's
more likely a typo I introduced few days ago which breaks
NV50 because SHLADD is not supported there.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Ilia Mirkin <imirkin@alum.mit.edu>
1 file changed