Hi,
From your question I gather your organisation does not have a competency frame work in place. This would provide a good indication of the behavior / competencies expected in each function.
Being jolly, smiling and joking can be considered as "People Friendly" as long as you address the task on hand, and not put it off with a joke always.
You cannot & perhaps should not change your behavior just to satisfy few people who feel something is not proper.
I suggest you focus on
a. HR Skills - are you the best HR in your firm and do people feel confident approaching you. This would include your recruitment, policy making, appraisal, training skills, etc.
b. Level of maturity - as visible through your behavior combined with Business knowledge. This is what does your company do and are you - the HR capable of supporting the business
c. Strategic thinking - based on your knowledge of business, HR and general wisdom
Hope this helps
Richard