staging: comedi: dt282x: Prefer using macro DIV_ROUND_UP

The macro DIV_ROUND_UP performs the computation
(((n) + (d) - 1) /(d)). It clarifies the divisor calculations.
This was done using the coccinelle script:
@@
expression e1;
expression e2;
@@
(
- ((e1) + e2 - 1) / (e2)
+ DIV_ROUND_UP(e1,e2)
|
- ((e1) + (e2 - 1)) / (e2)
+ DIV_ROUND_UP(e1,e2)
)

Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/dt282x.c

@@ -377,7 +377,7 @@ static unsigned int dt282x_ns_to_timer(unsigned int *ns, unsigned int flags)
 			divider = (*ns) / base;
 			break;
 		case CMDF_ROUND_UP:
-			divider = (*ns + base - 1) / base;
+			divider = DIV_ROUND_UP(*ns, base);
 			break;
 		}
 		if (divider < 256) {