Former Malaysian prime minister Mahathir Mohamad, 96, has been admitted to hospital for an elective medical procedure, the National Heart Institute said on Friday.It is the second time in as many months that Mahathir has been hospitalised at the specialist heart institute. The former premier, who has a history of heart problems and has undergone bypass surgery, was last admitted on December 16.Then, he was given a full medical check-up with several investigations but doctors discharged him a…