STYLE: adjust tutorial Allrun scripts (issue #310)

- A few without a 'cd' at the start.
  Use $(getApplication) directly in more places (for clarity).

tutorials/DNS/dnsFoam/boxTurb16/Allrun

@@ -4,12 +4,9 @@ cd ${0%/*} || exit 1    # Run from this directory
 # Source tutorial run functions
 . $WM_PROJECT_DIR/bin/tools/RunFunctions
 
-# Get application name
-application=$(getApplication)
-
 runApplication blockMesh
 runApplication boxTurb
-runApplication $application
+runApplication $(getApplication)
 runApplication -s enstrophy  postProcess -func enstrophy
 
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