STAGING: COMEDI: Remove unnecessary typecast of c90 int constant

This patch removes unnecessary typecast of c90 int constant.
Signed-off-by: Pablo G. Gallardo <pggllrd@gmail.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/comedi.h

@@ -516,7 +516,7 @@ struct comedi_bufinfo {
 #define UNIT_mA			1
 #define UNIT_none		2
 
-#define COMEDI_MIN_SPEED	((unsigned int)0xffffffff)
+#define COMEDI_MIN_SPEED	0xffffffffu
 
 /**********************************************************/
 /* everything after this line is ALPHA */