USB: Use core_param.

Found this when I changed args to __module_param_call.  We now have
core_param for exactly this.

This reverts to the 2005 (pre- aafbf24a) behaviour where "nousb" was
not a module parameter, just a kernel command line parameter.  That's
more sensible anyway.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Pete Zaitcev <zaitcev@redhat.com>
---
 drivers/usb/core/usb.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- linux-2.6.orig/drivers/usb/core/usb.c
+++ linux-2.6/drivers/usb/core/usb.c
@@ -963,7 +963,9 @@ void usb_buffer_unmap_sg(const struct us
 EXPORT_SYMBOL_GPL(usb_buffer_unmap_sg);
 
 /* format to disable USB on kernel command line is: nousb */
-__module_param_call("", nousb, param_set_bool, param_get_bool, &nousb, 0444);
+#ifndef MODULE
+core_param(nousb, nousb, bool, 0444);
+#endif
 
 /*
  * for external read access to <nousb>