staging: comedi: serial2002: Fix unnecessary cast styling issue

checkpatch.pl warns that a cast of 1 to (long long) is unnecessary.
Remove the cast and also add code to check and make sure that
maxdata_list[chan] is not shifted too far, as suggested by Ian
Abbott.

Signed-off-by Chris Cesare <chris.cesare@gmail.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/serial2002.c

@@ -379,7 +379,10 @@ static int serial2002_setup_subdevice(struct comedi_subdevice *s,
 				range_table_list[chan] =
 				    (const struct comedi_lrange *)&range[j];
 			}
-			maxdata_list[chan] = ((long long)1 << cfg[j].bits) - 1;
+			if (cfg[j].bits < 32)
+				maxdata_list[chan] = (1u << cfg[j].bits) - 1;
+			else
+				maxdata_list[chan] = 0xffffffff;
 			chan++;
 		}
 	}