Add missing @require_context
Add missing @require_context

@require_context wrapper is required to make sure the
functions must have the first param as RequestContext
to prevent misuage, the wrapper should be applied to
db functions otherwise we will send wrong info to
db layer function, add the wrapper would report
error eailer.

key_pair_count_by_user is similar to db other functions,
so it should have same decorateors the others have.
Because there is already a test for this wrapper.

Change-Id: I98efbf8347b0cf7bf21077c4654c47b666fe8dd9

rajalokan/nova,jianghuaw/nova,rajalokan/nova,rahulunair/nova,klmitch/nova,ted-gould/nova,alaski/nova,whitepages/nova,sebrandon1/nova,j-carpentier/nova,JianyuWang/nova,edulramirez/nova,rahulunair/nova,noironetworks/nova,MountainWei/nova,yosshy/nova,CCI-MOC/nova,BeyondTheClouds/nova,cloudbase/nova,cyx1231st/nova,gooddata/openstack-nova,klmitch/nova,jianghuaw/nova,TwinkleChawla/nova,nikesh-mahalka/nova,vmturbo/nova,CEG-FYP-OpenStack/scheduler,apporc/nova,CCI-MOC/nova,cernops/nova,NeCTAR-RC/nova,raildo/nova,ted-gould/nova,phenoxim/nova,gooddata/openstack-nova,mahak/nova,cernops/nova,mahak/nova,jianghuaw/nova,mahak/nova,gooddata/openstack-nova,dims/nova,felixma/nova,rajalokan/nova,shail2810/nova,Juniper/nova,bigswitch/nova,phenoxim/nova,hanlind/nova,klmitch/nova,rajalokan/nova,isyippee/nova,TwinkleChawla/nova,jianghuaw/nova,zhimin711/nova,gooddata/openstack-nova,vmturbo/nova,Juniper/nova,devendermishrajio/nova,cloudbase/nova,zhimin711/nova,BeyondTheClouds/nova,sebrandon1/nova,devendermishrajio/nova,fnordahl/nova,scripnichenko/nova,barnsnake351/nova,cloudbase/nova,j-carpentier/nova,cyx1231st/nova,klmitch/nova,fnordahl/nova,vmturbo/nova,shail2810/nova,Francis-Liu/animated-broccoli,openstack/nova,cernops/nova,mikalstill/nova,mikalstill/nova,yosshy/nova,hanlind/nova,CEG-FYP-OpenStack/scheduler,JianyuWang/nova,Juniper/nova,mmnelemane/nova,noironetworks/nova,openstack/nova,MountainWei/nova,mmnelemane/nova,sebrandon1/nova,NeCTAR-RC/nova,raildo/nova,edulramirez/nova,Juniper/nova,scripnichenko/nova,hanlind/nova,alaski/nova,bigswitch/nova,barnsnake351/nova,Francis-Liu/animated-broccoli,whitepages/nova,isyippee/nova,felixma/nova,apporc/nova,rahulunair/nova,openstack/nova,nikesh-mahalka/nova,dims/nova,mikalstill/nova,vmturbo/nova,BeyondTheClouds/nova