buildman: Drop the 'alive' flag in BuilderThread

This is not used, so drop it.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/buildman/builderthread.py b/tools/buildman/builderthread.py
index af4d15a..c4fe219 100644
--- a/tools/buildman/builderthread.py
+++ b/tools/buildman/builderthread.py
@@ -470,9 +470,7 @@
         This thread picks a job from the queue, runs it, and then goes to the
         next job.
         """
-        alive = True
         while True:
             job = self.builder.queue.get()
-            if alive:
-                self.RunJob(job)
+            self.RunJob(job)
             self.builder.queue.task_done()