drivers/staging/comedi/drivers/me4000.c: adjust suspicious bit operation

drivers/staging/comedi/drivers/me4000.c: adjust suspicious bit operation

TRIG_ROUND_NEAREST is 0, so a bit-and with it is always false.  The
value TRIG_ROUND_MASK covers the bits of the TRIG_ROUND constants, so
first pick those bits and then make the test using ==.

The same is done for TRIG_ROUND_UP for symmetry, even though bit-and would
be sufficient in this case.

This problem was found using Coccinelle (http://coccinelle.lip6.fr/).

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