ALSA: au88x0: fix incorrect left shift

vortex_wt_setdsout performs bit-negation on the bit position (wt&0x1f)
rather than on the resulting bitmask.  This code is never actually
invoked (vortex_wt_setdsout is always called with en=1), so this does
not currently cause any problem, and this patch is simply cleanup.
Signed-off-by: Nickolai Zeldovich <nickolai@csail.mit.edu>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/au88x0/au88x0_synth.c

@@ -58,7 +58,7 @@ static void vortex_wt_setdsout(vortex_t * vortex, u32 wt, int en)
 	if (en)
 		temp |= (1 << (wt & 0x1f));
 	else
-		temp &= (1 << ~(wt & 0x1f));
+		temp &= ~(1 << (wt & 0x1f));
 	hwwrite(vortex->mmio, WT_DSREG((wt >= 0x20) ? 1 : 0), temp);
 }