Update the timestamp setting script ti make shellcheck happy

bin/set-timestamps-from-git

@@ -6,11 +6,10 @@
 # This can be useful when build tools depend on file timestamps to
 # make caching decisions
 
-for file in $(find src examples -type f -print)
-do
-  timestamp=$(git log --pretty=format:%ad --date=format:%Y%m%d%H%M.%S -n 1 HEAD "$file" 2> /dev/null)
+find src examples -type f -exec sh -c '
+  timestamp=$(git log --pretty=format:%ad --date=format:%Y%m%d%H%M.%S -n 1 HEAD "$1" 2> /dev/null)
   if [ "x$timestamp" != "x" ]; then
-    touch -t "$timestamp" "$file"
+    touch -t "$timestamp" "$1"
   fi
-done
+' sh {} \;