foamSequenceVTKFiles: Avoid the -s and -a options for basename

Only recent GNU/Linux distributions support this functionality
Resolves bug-report http://www.openfoam.org/mantisbt/view.php?id=1947

bin/foamSequenceVTKFiles

@@ -94,7 +94,7 @@ if [ ! -d $DIR ]; then
 fi
 
 FILES=$(find $DIR -type f -name *vtk)
-NAMES=$(basename -s .vtk -a $FILES | sort -u)
+NAMES=$(for f in $FILES; do basename $f .vtk; done | sort -u)
 
 if [ -d $OUT ]; then
     echo "$OUT directory already exists.  Deleting links within it..."