use block_dev.get_bdm_swap_list in compute api
use block_dev.get_bdm_swap_list in compute api

get_bdm_swap_list in block_dev is created only used in test
either we remove it or use it. This patch makes compute api
use the function.

Change-Id: If90f74ec01b93ce2dce8e30073a221aa311c899b

Juniper/nova,CCI-MOC/nova,jianghuaw/nova,cloudbase/nova,klmitch/nova,cernops/nova,klmitch/nova,edulramirez/nova,hanlind/nova,rahulunair/nova,yosshy/nova,openstack/nova,hanlind/nova,mahak/nova,devendermishrajio/nova,Francis-Liu/animated-broccoli,mikalstill/nova,fnordahl/nova,j-carpentier/nova,bigswitch/nova,cloudbase/nova,zhimin711/nova,isyippee/nova,BeyondTheClouds/nova,Juniper/nova,Juniper/nova,phenoxim/nova,yosshy/nova,klmitch/nova,scripnichenko/nova,raildo/nova,cernops/nova,CEG-FYP-OpenStack/scheduler,rajalokan/nova,dims/nova,ted-gould/nova,TwinkleChawla/nova,CCI-MOC/nova,raildo/nova,vmturbo/nova,alaski/nova,rajalokan/nova,apporc/nova,cloudbase/nova,mikalstill/nova,jianghuaw/nova,rahulunair/nova,alaski/nova,devendermishrajio/nova,MountainWei/nova,noironetworks/nova,nikesh-mahalka/nova,NeCTAR-RC/nova,cyx1231st/nova,zhimin711/nova,gooddata/openstack-nova,fnordahl/nova,sebrandon1/nova,mahak/nova,nikesh-mahalka/nova,gooddata/openstack-nova,TwinkleChawla/nova,Francis-Liu/animated-broccoli,gooddata/openstack-nova,noironetworks/nova,MountainWei/nova,Juniper/nova,mahak/nova,BeyondTheClouds/nova,rajalokan/nova,felixma/nova,felixma/nova,vmturbo/nova,jianghuaw/nova,ted-gould/nova,rajalokan/nova,openstack/nova,gooddata/openstack-nova,edulramirez/nova,klmitch/nova,jianghuaw/nova,phenoxim/nova,vmturbo/nova,hanlind/nova,rahulunair/nova,scripnichenko/nova,apporc/nova,vmturbo/nova,BeyondTheClouds/nova,cyx1231st/nova,NeCTAR-RC/nova,openstack/nova,sebrandon1/nova,j-carpentier/nova,bigswitch/nova,dims/nova,sebrandon1/nova,cernops/nova,JianyuWang/nova,mikalstill/nova,CEG-FYP-OpenStack/scheduler,isyippee/nova,JianyuWang/nova