usb: core: Fix file path that does not exist

Both driver.c and generic.c are not under drivers/usb/, should
be drivers/usb/core/ instead.

Signed-off-by: Wei Ming Chen <jj251510319013@gmail.com>
Link: https://lore.kernel.org/r/20211205023529.91165-1-jj251510319013@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>