include: remove FI_INJECT_* macros

We should just remove the tests for individual operations and let the
FI_INJECT flag indicate that inject operations are supported for all
interfaces supported by an endpoint.

Signed-off-by: Sayantan Sur <sayantan.sur@intel.com>
Merge pull request #100 from sayantansur/remove-fi-inject-msg

include: remove FI_INJECT_* macros