Staging: rt2860,rt2870: Correct use of ! and &

IW_ENCODE_MODE is 0xF000 and thus !erq->flags & IW_ENCODE_MODE is always 0.
I assume that !(erq->flags & IW_ENCODE_MODE) 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>