Mark Wahlberg does well by buddy pictures, and while “Pain & Gain” seems to qualify as this year’s model, with both Anthony Mackie and Dwayne Johnson as “buddies,” there’s also “Two Guns,” which pairs Wahlberg up with Denzel Washington in a”48 Hours” style reluctant partnership action comedy. This one opens Aug. 2, and has Paula Patton, Edward James Olmos and Bill Paxton in the supporting cast. Two government agents, commissioned by different agencies, to knock over a bank, are forced to work together to figure out whose money their agencies wanted them to steal.