bitbake/runqueue.py: Ensure we fully process the covered list

[Richard Purdie <richard.purdie@linuxfoundation.org>]

The existing looping code can mask an existing "found = True"
by forcing it to False each time. This can lead to dependency
lists not being fully searched and results in dependency errors.

An exmaple of this was the autobuilder building linux-yocto from
sstate but then rebuilding some of the recipe's tasks for no
apparent reason. Separating the logic into two variables solves this
problem since any "found = True" value is now always preserved.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
---
diff --git a/bitbake/lib/bb/runqueue.py b/bitbake/lib/bb/runqueue.py
index 98124af..54b1c86 100644
--- a/bitbake/lib/bb/runqueue.py
+++ b/bitbake/lib/bb/runqueue.py
@@ -1211,12 +1211,13 @@ class RunQueueExecuteTasks(RunQueueExecute):
                 if task in self.rq.scenequeue_covered:
                     continue
                 if len(self.rqdata.runq_revdeps[task]) > 0 and self.rqdata.runq_revdeps[task].issubset(self.rq.scenequeue_covered):
-                    found = True
+                    ok = True
                     for revdep in self.rqdata.runq_revdeps[task]:
                         if self.rqdata.runq_fnid[task] != self.rqdata.runq_fnid[revdep]:
-                            found = False
+                            ok = False
                             break
-                    if found:
+                    if ok:
+                        found = True
                         self.rq.scenequeue_covered.add(task)
 
         # Detect when the real task needs to be run anyway by looking to see