Sen. Charles Schumer’s brother-in-law was quietly nominated this month to a federal judgeship in New Jersey — a move that has some in the Garden State crying political foul, The Post has learned. Kevin McNulty, who is married to Schumer’s sister, Fran, was named to the US District Court by the White House late on Friday, Dec. 16. According to a boilerplate quote, President Obama believes McNulty is a “distinguished individual” who “will serve the American people with integrity and a steadfast commitment to justice.”