usb: remove junk from store_remove_id

retval is 0, and carefully assigned - and tested as non zero.

This is not useful. While we are at it remove some other bogus initialisation
in the function

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>