xhci: check slot_id is valid before gathering slot info

xhci: check slot_id is valid before gathering slot info

Check that the slot_id that we dug out from command completion event
TRB, is valid before using it to identify the slot associated with the
command that generated the event.

Signed-off-by: Lalithambika Krishna Kumar <lalithambika.krishnakumar@intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-11-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>