show 'Too many matches' error at the end of the result.

Once we search in a big file, sometimes face "Too many matches" error at the head of the result as follows:

$ ag "foo" error.log
ERR: Too many matches in catalogd.INFO. Skipping the rest of this file.
...result...
...result...
...

While there's no message that it just reached the limit at the end of the result and this usually makes confusing that ag would not miss the result. This change will make a change to show the error message at the end of the result.