Here is my thought on it because I am currently going hrough it right now. Me and 4 of my golf buddies had a bet at the beginning of the year for $500 to who could lose the most % weight in 4 months (Jan1 to April 1). I was 242 lbs, the heaviest I had ever been. I completely changed my diet, gave up a lot of things, did a rediculous amount of cardio every day, and lifted weights every day - light weights / a lot of reps. On April 1st, I weighed in at 195. 47 lbs lost, won the bet by 6 lbs. I know this was a lot of weight in a shorter amount of time, but I did it the right way, and I haven't gained any in the month after. I used to be a gym rat, so my muscle memory is taking in effect now. But now my swing feels great! More flexability, and nothing in the way to restrict it. I am hitting my irons the best I ever have!
But all in all, lifting weights is a great idea if you do it in moderation. Don't try to be a body builder. Focus on your core is a must. But, lifting weights is one of the best ways to burn calories - if you eat right u will lose weight - will become leaner - couldn't hurt your golf game.