staging: unisys: visorbus: remove unnecessary poll_count logic

The use of poll_count is a vestige from long-ago testing, which is no
longer needed.  It is removed by this patch.

Signed-off-by: Tim Sell <Timothy.Sell@unisys.com>
Signed-off-by: David Kershner <david.kershner@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>