Mechanical cleanup to SouthboundIT

* dataBroker can be turned into a local variable
* "frmo" -> "from"
* drop a couple of variables used only for return
* Javadoc corrections
* remove commented Assume calls which have corresponding Assert calls
* reduce the scope of variables where appropriate
* fix an impossible equals assert (dpTypeStr -> dpType compared to a
  DatapathTypeBase class)
* Java 7 <> operator
* remove unnecessary casts and boxing
* correct a format string ("%s_%s_d" -> "%s_%s_%d")

Change-Id: I9a7da21a9252c3f256a0230521402ced3fffb774
Signed-off-by: Stephen Kitt <skitt@redhat.com>