DMX is entering an inpatient rehab program, a court filing indicates. The rapper, whose birth name is Earl Simmons, tested positive for cocaine and pot several times while out on bail for his federal tax fraud case. Manhattan Federal Judge Jed Rakoff ordered him to home confinement following the failed drug tests. Shortly thereafter, DMX asked Rakoff for approval to travel for work. Rakoff decided Friday that DMX could travel to Atlanta for a gig — as long as he was with a sober coach at all times. DMX’s Atlanta job fell through, however, he decided to enter an inpatient substance-abuse program, according to his lawyer, Murray Richman. “This is a…