project: print logs from the correct job

`enumerate` on `imap_unordered` does (obviously) not return the index of the
element that finished processing.
That resulted in printing the wrong log file which might not even be finished
and thus swallowing future logs of that job.

Instead, let each job return it's index.

Fixes: #528
Signed-off-by: Michael Zimmermann <sigmaepsilon92@gmail.com>

src/west/app/project.py

@@ -858,7 +858,7 @@ class Update(_ProjectCommand):
 
     @staticmethod
     def _update_concurrent_thread(args):
-        project, self, logdir = args
+        index, project, self, logdir = args
         if logdir:
             saved_stdout = os.dup(sys.stdout.fileno())
             saved_stderr = os.dup(sys.stderr.fileno())
@@ -872,9 +872,9 @@ class Update(_ProjectCommand):
 
         try:
             self.update(project)
-            return True
+            return (index, True)
         except subprocess.CalledProcessError:
-            return False
+            return (index, False)
         finally:
             if logdir:
                 sys.stdout.flush()
@@ -902,13 +902,12 @@ class Update(_ProjectCommand):
             log.dbg(f"log directory: {logdir_name}")
 
         args = []
-        for project in projects:
-            args.append((project, self, logdir_name))
+        for index, project in enumerate(projects):
+            args.append((index, project, self, logdir_name))
 
         with multiprocessing.Pool(self.args.jobs) as p:
-            for index, successful in enumerate(
-                    p.imap_unordered(self._update_concurrent_thread,
-                                     args)):
+            for index, successful in p.imap_unordered(
+                                     self._update_concurrent_thread, args):
                 project = projects[index]
 
                 if logdir: