man pages: FI_SEND_BUFFERED -> FI_INJECT, remove sendto/recvfrom refs

Signed-off-by: Reese Faucette <rfaucett@cisco.com>
Merge pull request #349 from rfaucett/pr/fi_man

man pages: FI_SEND_BUFFERED -> FI_INJECT, remove sendto/recvfrom refs