ofed: don't expose symbols twice

ibv_init_wq and ibv_cleanup_wq are made visible with the
default_symver which puts them in the IBVERBS_1.1 ABI. Don't
try to expose them as IBVERBS_PRIVATE_14 symbols as GNU ld
complains with --no-undefined-symbol.

Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D45090