staging: comedi: don't dereference user memory for INSN_INTTRIG

`parse_insn()` is dereferencing the user-space pointer `insn->data`
directly when handling the `INSN_INTTRIG` comedi instruction. It
shouldn't be using `insn->data` at all; it should be using the separate
`data` pointer passed to the function. Fix it.

Cc: stable <[e-mail]>
Signed-off-by: Ian Abbott <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/comedi/comedi_fops.c

···
 				ret = -EAGAIN;
 				break;
 			}
-			ret = s->async->inttrig(dev, s, insn->data[0]);
+			ret = s->async->inttrig(dev, s, data[0]);
 			if (ret >= 0)
 				ret = 1;
 			break;