Bluetooth: delete a stray unlock

Bluetooth: delete a stray unlock

BugLink: https://bugs.launchpad.net/bugs/1860125
commit df66499a1fab340c167250a5743931dc50d5f0fa upstream.

We used to take a lock in amp_physical_cfm() but then we moved it to
the caller function.  Unfortunately the unlock on this error path was
overlooked so it leads to a double unlock.

Fixes: a514b17fab51 ("Bluetooth: Refactor locking in amp_physical_cfm")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>