dev-manual, kernel-dev, ref-manual: Updated task name usage.

There was inconsistency on how we refer to a task name throughout
the YP manual set.  The proper way is "do_<taskname>".  Some
occurrences did not include the "do_" prefix.  These have been
fixed.

(From yocto-docs rev: b32821bb0d3e6de7bca68b25c662a023526a10c4)

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/ref-manual/technical-details.xml

@@ -442,11 +442,11 @@
             works on a per-task basis rather than a per-recipe basis.
             You might wonder why using a per-task basis is preferred over a per-recipe basis.
             To help explain, consider having the IPK packaging backend enabled and then switching to DEB.
-            In this case,
+            In this case, the
             <link linkend='ref-tasks-install'><filename>do_install</filename></link>
             and
             <link linkend='ref-tasks-package'><filename>do_package</filename></link>
-            outputs are still valid.
+            task outputs are still valid.
             However, with a per-recipe approach, the build would not include the
             <filename>.deb</filename> files.
             Consequently, you would have to invalidate the whole build and rerun it.