This is a stable-only fix for the backport of commit 5d9b70f7d5
("xhci: Don't add a virt_dev to the devs array before it's fully
allocated").
In branches that predate commit c5628a2af8 ("xhci: remove endpoint
ring cache") there is an additional failure path in
xhci_alloc_virt_device() where ring cache allocation fails, in
which case we need to free the ring allocated for endpoint 0.
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Cc: Mathias Nyman <mathias.nyman@intel.com>
Ben Hutchings
66bb6c2c44