STYLE: remove unnecessary stdout, stderr /dev/null redirects

- no stderr redirect needed:
    * 'command -v'

- no stdout/stderr redirect needed:
    * 'rm -f'

STYLE: consistent spacing after redirects

tutorials/verificationAndValidation/turbulentInflow/createGraphs

@@ -2,7 +2,7 @@
 cd ${0%/*} || exit 1                        # Run from this directory
 
 # Require gnuplot
-command -v gnuplot >/dev/null 2>&1 || {
+command -v gnuplot >/dev/null || {
     echo "gnuplot not found - skipping graph creation" 1>&2
     exit 1
 }