By Guy Faulconbridge MOSCOW (Reuters) – Some Russian officers fighting in Ukraine are unhappy with the military top brass and President Vladimir Putin because of the poor execution of the war, an influential nationalist Russian blogger said after visiting the conflict zone. Nearly 10 months since Putin ordered troops into Ukraine, there is no end in sight to the deadliest conflict in Europe since World War Two. In modern Russia, direct public criticism of Putin is rare though nationalist bloggers have been outspoken about the conduct of the war, especially the costly Russian defeats in Ukraine…