staging: wilc1000: rename u32count in wilc_setup_multicast_filter

This patch renames u32count to count to remove u32 prefix.
There is no need to use this prefix to show data type of this argument.

Signed-off-by: Chaehyun Lim <chaehyun.lim@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>