staging: vme_user: use an unsigned int for counting the number of kparams

unsigned int is what struct kparam_array internally uses.
Signed-off-by: Emilio G. Cota <cota@braap.org>
Acked-by: Martyn Welch <martyn.welch@ge.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/vme/devices/vme_user.c

@@ -44,7 +44,7 @@ static DEFINE_MUTEX(vme_user_mutex);
 static char driver_name[] = "vme_user";
 
 static int bus[USER_BUS_MAX];
-static int bus_num;
+static unsigned int bus_num;
 
 /* Currently Documentation/devices.txt defines the following for VME:
  *