counsel.el (counsel-git-grep-recenter): fix warning by recenter

[edkolev]

Without this fix, C-l (in counsel-git-grep-map) would print the warning:
`recenter'ing a window that does not display current-buffer.

[edkolev]

I had the following issue:

• run counsel-git-grep
• C-l on a grep result of a file not displayed in a buffer
• the window correctly switches to a fresh buffer and recenters, however, the following error is displayed recenter'ing a window that does not display current-buffer. (printed by emacs' window.c)

This PR moves counsel-git-grep-action out of the with-ivy-window macro (counsel-git-grep-action calls itself this macro) and leaves recenter-top-bottom the sole function called in ivy-with-window -- with this change the warning from window.c isn't displayed

[abo-abo]

Thanks.