Change this code to downgrade FCV to 4.2 when the test left FCV at "upgrading to 4.4".

SERVER-37074 recently made changes to the validate hook to handle the case where FCV is in the middle of being downgraded: "downgrading to 4.2", {version: 4.4, targetVersion:4.2}. However, it also added code such that the hook won't set FCV to 4.2 if FCV is in the middle of being upgraded: "upgrading to 4.4", {version: 4.2, targetVersion:4.4}. It now only sets FCV 4.2 if the test left the FCV at "fully upgraded to 4.4", {version: 4.4}.

Should probably change the if-statement to "if (originalFCV.targerVersion != requiredFCV) setFCV(requiredFCV)"