[Libomptarget][NFC] Format in-line comments consistently (#77530)

Summary:
The LLVM style uses /*Foo=*/ when indicating the name of a constant. See
https://llvm.org/docs/CodingStandards.html#comment-formatting. This is
useful for consistency, as well as because `clang-format` understands
this syntax and formats it more cleanly. Do a bulk update of this
syntax.
GitOrigin-RevId: d03b8c3a048262eae1b13be829e20971e1714ade
17 files changed