convert echo to printf

doasedit

@@ -1,12 +1,12 @@
 #!/bin/sh
 if [ -n "${2}" ]; then
-	echo "Expected only one argument"
+	printf 'Expected only one argument\n'
 	exit 1
 elif [ -z "${1}" ]; then
-	echo "No file path provided"
+	printf 'No file path provided\n'
 	exit 1
 elif [ "$(id -u)" -eq 0 ]; then
-	echo "Cannot be run as root"
+	printf 'Cannot be run as root\n'
 	exit 1
 fi
 
@@ -35,7 +35,7 @@ $EDITOR "$tempdir"/edit
 doas tee "$tempdir"/file 1>/dev/null < "$tempdir"/edit
 
 if doas cmp -s "$tempdir/file" "$srcfile"; then
-	echo "Skipping write; no changes."
+	printf 'Skipping write; no changes.\n'
 	exit 0
 else
 	doas mv -f "$tempdir"/file "$srcfile"