usbip: Fix vhci_urb_enqueue() URB null transfer buffer error path

usbip: Fix vhci_urb_enqueue() URB null transfer buffer error path

BugLink: https://bugs.launchpad.net/bugs/1853519
commit 2c904963b1dd2acd4bc785b6c72e10a6283c2081 upstream.

Fix vhci_urb_enqueue() to print debug msg and return error instead of
failing with BUG_ON.

Signed-off-by: Shuah Khan <shuah@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>