Some doc typo fixes

All should be clear enough, except perhaps committish / commitish.
I just kept the more-used one within the current docs.

[jc: with rephrasing of check-ref-format description later discussed
 on the list]

Signed-off-by: Francis Daly <francis@daoine.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 1 insertions, 1 deletions

diff --git a/Documentation/hooks.txt b/Documentation/hooks.txt
index e3dde39..898b4aa 100644
--- a/Documentation/hooks.txt
+++ b/Documentation/hooks.txt
@@ -100,7 +100,7 @@ update
 This hook is invoked by `git-receive-pack` on the remote repository,
 which is happens when a `git push` is done on a local repository.
 Just before updating the ref on the remote repository, the update hook
-is invoked.  It's exit status determines the success or failure of
+is invoked.  Its exit status determines the success or failure of
 the ref update.
 
 The hook executes once for each ref to be updated, and takes