rdm_pingping:  fix fi_av_insert() return code checking
also allow fabric selection with -f and print fabric in use

Signed-off-by: Reese Faucette <rfaucett@cisco.com>
Merge pull request #93 from rfaucett/pr/rdmpp

rdm_pingping:  fix fi_av_insert() return code checking
Merge remote branch 'upstream/master' into multi_recv
Merge branch 'multi_recv' of https://github.com/shantonu/fabtests into multi_recv