bnxt_en: Minor formatting changes in FW devlink_health_reporter

Minor formatting changes to diagnose cb for FW devlink health
reporter.

Suggested-by: Jiri Pirko <jiri@mellanox.com>
Cc: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Vasundhara Volam <vasundhara-v.volam@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>