Revert "libpmc: jevents: Partial style(9) pass"

This file is shared with Linux. Having local style patches does not
help with updating it.

This reverts commit 3ea691c2612952dc5e6963649ad64312bd6dff4f.

(cherry picked from commit 51f329660f1c56f295fb13bb3a34fb0895f485a1)