Bridge: Fix the specification of the getAllTasks return value

Change-Id: Ibf4dfacf9917a51a2d98433e5fa9a4bc5e1fe785
Signed-off-by: Adam Litke <agl@us.ibm.com>
Reviewed-on: http://gerrit.ovirt.org/11336
Reviewed-by: ShaoHe Feng <shaohef@linux.vnet.ibm.com>
Tested-by: ShaoHe Feng <shaohef@linux.vnet.ibm.com>