core.job_id: rename get_job_id() to create_unique_job_id()

The name get_job_id() doesn't reflect the fact that this
function returns a new job ID everytime it's called.

avocado/core/data_dir.py

@@ -209,7 +209,7 @@ def get_job_logs_dir(args=None, unique_id=None):
         logdir = get_logs_dir()
     # Stand alone tests handling
     if unique_id is None:
-        unique_id = job_id.get_job_id()
+        unique_id = job_id.create_unique_job_id()
 
     debugbase = 'job-%s-%s' % (start_time, unique_id[:7])
     debugdir = path.init_dir(logdir, debugbase)

avocado/core/job_id.py

@@ -21,7 +21,7 @@ _RAND_POOL = random.SystemRandom()
 _HOSTNAME = socket.gethostname()
 
 
-def get_job_id():
+def create_unique_job_id():
     """
     Create a job ID SHA1.
 

avocado/job.py

@@ -283,9 +283,9 @@ class Job(object):
         """
         self.args = args
         if args is not None:
-            self.unique_id = args.unique_job_id or job_id.get_job_id()
+            self.unique_id = args.unique_job_id or job_id.create_unique_job_id()
         else:
-            self.unique_id = job_id.get_job_id()
+            self.unique_id = job_id.create_unique_job_id()
         self.logdir = data_dir.get_job_logs_dir(self.args, self.unique_id)
         self.logfile = os.path.join(self.logdir, "job.log")
         self.idfile = os.path.join(self.logdir, "id")