Staging: comedi: Correct use of ! and &

0x20 has 0 as its rightmost bit and thus !inl(info->plx_regbase +
PLX_INTCSR) & 0x20 is always 0.  I assume that !(!inl(info->plx_regbase +
PLX_INTCSR) & 0x20) was intended.

The semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/

)

// <smpl>
@@ expression E; constant C; @@
(
  !E & !C
|
- !E & C
+ !(E & C)
)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>