Fix spelling errors in code comments

Reported-by: Jens Schleusener <Jens.Schleusener@fossies.org>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/hooks/post-receive-email

@@ -329,7 +329,7 @@ generate_update_branch_email()
 	#
 	#  git rev-parse --not --all | grep -v $(git rev-parse $refname)
 	#
-	# Get's us to something pretty safe (apart from the small time
+	# Gets us to something pretty safe (apart from the small time
 	# between refname being read, and git rev-parse running - for that,
 	# I give up)
 	#