net: caif: fix memory leak in caif_device_notify

In case of caif_enroll_dev() fail, allocated
link_support won't be assigned to the corresponding
structure. So simply free allocated pointer in case
of error

Fixes: 7c18d220

 ("caif: Restructure how link caif link layer enroll")
Cc: stable@vger.kernel.org
Reported-and-tested-by:  <syzbot+7ec324747ce876a29db6@syzkaller.appspotmail.com>
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>