thunderbolt: Fix to check the return value of kmemdup

commit fd21b79e

 upstream.

uuid in add_switch is allocted via kmemdup which can fail. The patch
logs the error and cleans up the allocated memory for switch.

Signed-off-by: Aditya Pakki <pakki001@umn.edu>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
[PG: "goto out"  ---> "return" for older 4.18.x code base.]
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>