Improve #12920 fix (#13958)

tools/nimgrep.nim

@@ -412,6 +412,8 @@ proc processFile(pattern; filename: string; counter: var int, errors: var int) =
       else:
         printContextBetween(si, prevMi, curMi)
       printMatch(si.fileName, curMi)
+      if t.last == buffer.len - 1:
+        stdout.write("\n")
       stdout.flushFile()
     else:
       let r = replace(curMi.match, pattern, replacement % matches)
@@ -659,8 +661,6 @@ else:
       walker(rep, f, counter, errors)
   if errors != 0:
     printError $errors & " errors"
-  if counter == 1:
-    stdout.write("\n")
   stdout.write($counter & " matches\n")
   if errors != 0:
     quit(1)