usb: PS3 EHCI remove unneeded ehci_shutdown

Remove an unneeded call to ehci_shutdown() in ps3_ehci_remove().
This removal will allow for a loadable ehci driver.

Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Geoff Levand <geoff@infradead.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>