There’s a shining moment in this uneven spin on Grumpy Old Men when Bernie Mac and Samuel L. Jackson, playing feuding backup singers on an R&B comeback tour, stop in the desert to change a flat tire. Instead, they break into an impromptu version of the soul classic “I’m Your Puppet,” riffing off each other with waves of affection that flow right off the screen. Mac died shortly after wrapping the movie, as did Isaac Hayes, who does a cameo as himself. Soul Men is a chance to salute these masters of mirth and music. Take it.