salt - minion.erb - fix compiler warnings

Warning: Variable access via 'salt_master' is deprecated.
Use '@salt_master' instead.
   (at /modules/salt/templates/minion.erb:11:in `result')

Warning: Variable access via 'salt_master' is deprecated.
Use '@salt_master' instead.
   (at /modules/salt/templates/minion.erb:17:in `result')

Warning: Variable access via 'salt_client_id' is deprecated.
Use '@salt_client_id' instead.
   (at /modules/salt/templates/minion.erb:46:in `result')

Warning: Variable access via 'salt_grains' is deprecated.
Use '@salt_grains' instead.
   (at /modules/salt/templates/minion.erb:63:in `result')

Warning: Variable access via 'salt_grains' is deprecated.
Use '@salt_grains' instead.
   (at /modules/salt/templates/minion.erb:64:in `result')

Warning: Variable access via 'salt_dns_check' is deprecated.
Use '@salt_dns_check' instead.
   (at /modules/salt/templates/minion.erb:118:in `result')

Warning: Variable access via 'salt_master_finger' is deprecated.
Use '@salt_master_finger' instead.
   (at /puppet/modules/salt/templates/minion.erb:300:in `result')

Change-Id: I5dd0ad6909091893e2d1dc9e9cd232f1e0472355
Merge "salt - minion.erb - fix compiler warnings" into production