Fix hldiff regex for short stats

contrib/hldiff

@@ -1,4 +1,5 @@
 #!/usr/bin/env -S awk -f
+# vim: set ft=awk :
 BEGIN {
 	bright = "\x1B[1m"
 	red = "\x1B[31m"

contrib/plaintext

@@ -1,4 +1,5 @@
 #!/usr/bin/env -S awk -f
+# vim: set ft=awk :
 BEGIN {
 	dim = "\x1B[2m"
 	cyan = "\x1B[36m"