nvc0/ir: fix wrong emission of (a OP b) OP c

nvc0/ir: fix wrong emission of (a OP b) OP c

The third source must be emitted at offset 49 instead of 17 and the
not modifier is at 52 instead of 20. If you look a bit above in
emitLogicOp() you will see that the dest is emitted at 17 which
confirms that src(2) is obviously wrong.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Ilia Mirkin <imirkin@alum.mit.edu>
Cc: "11.1 11.2" <mesa-stable@lists.freedesktop.org>