Handle repeated calls to halide_dev_malloc correctly
Handle repeated calls to halide_dev_malloc correctly


Former-commit-id: b93ab2a514d59c690cb4367f5d125f9f4feaad8f
darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide