Removed deletion of salt by 'password' lookup

Removed deletion of salt param from lookup file by 'password' lookup_filter.
Old behaviour leads to constant changed status when two tasks uses same lookup,
one with 'encrypt' parameter, and other without.

For example:

    tasks:
      - name: Create user
        user:
          password: "{{ lookup('password', inventory_dir + '/creds/user/pass' ncrypt=sha512_crypt) }}"
          ...
    # Lookup file 'creds/user/pass' now contain password with salt
      - name: Create htpasswd
        htpasswd:
          password: "{{ lookup('password', inventory_dir + '/creds/user/pass') }}"
          ...
    # Salt gets deleted from lookup file 'creds/user/pass'
    # Next run of "Create user" task will create it again and will have 'changed' status

lib/ansible/plugins/lookup/password.py

@@ -150,11 +150,6 @@ class LookupModule(LookupBase):
                     with open(path, 'w') as f:
                         os.chmod(path, 0o600)
                         f.write(content + '\n')
-                # crypt not requested, remove salt if present
-                elif (params['encrypt'] is None and salt):
-                    with open(path, 'w') as f:
-                        os.chmod(path, 0o600)
-                        f.write(password + '\n')
 
             if params['encrypt']:
                 password = do_encrypt(password, params['encrypt'], salt=salt)