Use REFCOUNT_COUNT() to obtain refcount where appropriate.
Refcount waiting will set some flag bits in the refcount value.
Make sure these bits get cleared by using the REFCOUNT_COUNT()
macro to obtain the actual refcount.

Differential Revision: https://reviews.freebsd.org/D21620
Reviewed by: kib@, markj@
MFC after: 1 week
Sponsored by: Mellanox Technologies