Police who shot and killed a hostage they mistakenly thought was the hostage-taker are shielded from liability for their actions, a federal appeals court held.The 7th U.S. Circuit Court of Appeals this week declined to revive a lawsuit accusing police in Neenah, Wis., of using excessive force on Michael Funk in violation of the Fourth Amendment.The court held officers Craig Hoffer and Robert Ross are entitled to qualified immunity because their actions did not violate any right that had been clearly established at the time …