Cleans the method init_engine

Reasons:
- init_engine contains code after return statement,
  which is of no use.
- the statements used are also of no purpose as
  they use unavailable variables.

Change:
- Code lines after return statement are removed.

Change-Id: Ibfd1f0de1d9200c0f1a724345fa9ef744da1ce7e
Closes-Bug: #1261169
Changes command to create the directory

Reasons:
- os.makedirs since running under normal user access
  will not be able to create the directory at
  root locations like /var/lib.

Changes:
- Used utils.execute like used at other places
  for working under root access.
- Test changed to test utils.execute instead of os.makedirs

Change-Id: Ie2313ae4cc22ac4a9baa4d8e099080f227a980c4
Closes-Bug: #1261492
Merge "Cleans the method init_engine"
Merge "Changes command to create the directory"