staging: usbip: vhci_hcd.c: rename init and exit functions

Change the prefix of the __init and __exit functions to vhci_hcd_ to
correspond with the modules name. And change the suffix of the __exit
function to exit instead of cleanup.

Signed-off-by: matt mooney <mfm@muteddisk.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>