HID: steam: fixes race in handling device list.

HID: steam: fixes race in handling device list.

[ Upstream commit 2d3f53a80e4eed078669853a178ed96d88f74143 ]

Using uhid and KASAN this driver crashed because it was getting
several connection events where it only expected one. Then the
device was added several times to the static device list and it got
corrupted.

This patch checks if the device is already in the list before adding
it.

Signed-off-by: Rodrigo Rivas Costa <rodrigorivascosta@gmail.com>
Tested-by: Siarhei Vishniakou <svv@google.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>