The Knicks have had some games this season when they’ve lost their composure and focus, and so now they’ve brought in a veteran player who is the first to admit, “I’m a hothead a little bit.” Sounds like a perfect fit. Kenyon Martin went through his first workout Saturday with the Knicks, but didn’t lose his temper or get on anyone’s bad side by saying the wrong thing after signing a 10-day contract. So he’s off to a good start and vows to continue, and plans on getting signed for the remainder of the season. “People have misconceptions about me,” the former Net said in Greenburgh. “That’s why I’m here, to change those now.'” Well, there’s more to it, from the slumping Knicks’ standpoint. They are hopeful that Martin can provide some hustle and defense, something they desperately need, along with insurance, with Marcus Camby and Rasheed Wallace still sidelined with injuries. If Martin sees any action Sunday against the Sixers when the Knicks try to snap a four-game losing streak, the longest during Mike Woodson’s tenure in New York, it will be very limited.