Fix pointer/int cast in USB devio code, and thus avoid a compiler warning.

A void* data argument passed to bus_find_device() and thence to match_devt()
is used to carry a 32-bit datum.  However, casting directly between a u32 and
a pointer is not permitted - there must be an intermediate cast via (unsigned)
long.

This was introduced by the following patch:

	commit 94b1c9fa060ece2c8f080583beb6cc6008e41413
	Author: Alan Stern <stern@rowland.harvard.edu>
	Date:   Tue Jun 24 14:47:12 2008 -0400

	    usbfs: simplify the lookup-by-minor routines

	    This patch (as1105) simplifies the lookup-by-minor-number code in
	    usbfs.  Instead of passing the minor number to the callback, which
	    must then reconstruct the entire dev_t value, the patch passes the
	    dev_t value directly.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>