controller/scheduler: Add nil check for host client lookup
controller/scheduler: Add nil check for host client lookup

Signed-off-by: Jonathan Rudenberg <3692bfa45759a67d83aedf0045f6cb635a966abf@titanous.com>

rikur/flynn,GrimDerp/flynn,benbjohnson/flynn,ozum/flynn,supermario/flynn,kgrz/flynn,whouses/flynn,GrimDerp/flynn,whouses/flynn,technosophos/flynn,clifff/flynn,justintung/flynn,justintung/flynn,ozum/flynn,flynn/flynn,supermario/flynn,benbjohnson/flynn,clifff/flynn,jzila/flynn,rikur/flynn,benbjohnson/flynn,rikur/flynn,rikur/flynn,technosophos/flynn,Brandywine2161/flynn,josephglanville/flynn,shads196770/flynn,jzila/flynn,Brandywine2161/flynn,philiplb/flynn,kgrz/flynn,justintung/flynn,pkdevbox/flynn,schatt/flynn,Brandywine2161/flynn,philiplb/flynn,josephglanville/flynn,kgrz/flynn,pkdevbox/flynn,flynn/flynn,benbjohnson/flynn,ozum/flynn,schatt/flynn,supermario/flynn,whouses/flynn,TribeMedia/flynn,lmars/flynn,schatt/flynn,shads196770/flynn,josephglanville/flynn,supermario/flynn,clifff/flynn,jzila/flynn,kgrz/flynn,Brandywine2161/flynn,Brandywine2161/flynn,justintung/flynn,lmars/flynn,josephglanville/flynn,kgrz/flynn,shads196770/flynn,josephglanville/flynn,shads196770/flynn,whouses/flynn,whouses/flynn,justintung/flynn,kgrz/flynn,ozum/flynn,rikur/flynn,pkdevbox/flynn,clifff/flynn,technosophos/flynn,pkdevbox/flynn,schatt/flynn,technosophos/flynn,philiplb/flynn,rikur/flynn,supermario/flynn,clifff/flynn,TribeMedia/flynn,GrimDerp/flynn,pkdevbox/flynn,GrimDerp/flynn,shads196770/flynn,jzila/flynn,benbjohnson/flynn,jzila/flynn,flynn/flynn,schatt/flynn,technosophos/flynn,clifff/flynn,jzila/flynn,justintung/flynn,TribeMedia/flynn,TribeMedia/flynn,schatt/flynn,GrimDerp/flynn,pkdevbox/flynn,lmars/flynn,flynn/flynn,TribeMedia/flynn,flynn/flynn,philiplb/flynn,philiplb/flynn,josephglanville/flynn,shads196770/flynn,ozum/flynn,lmars/flynn,Brandywine2161/flynn,TribeMedia/flynn,whouses/flynn,GrimDerp/flynn,supermario/flynn,lmars/flynn,benbjohnson/flynn,ozum/flynn