fs: dlm: fix possible use after free if tracing

This patch fixes a possible use after free if tracing for the specific
event is enabled. To avoid the use after free we introduce a out_put
label like all other user lock specific requests and safe in a boolean
to do a put or not which depends on the execution path of
dlm_user_request().

Cc: stable@vger.kernel.org
Fixes: 7a3de732

 ("fs: dlm: trace user space callbacks")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>