[cairo] Fixes for "it's" typos in comments

[Chris Wilson]

On Thu, 2009-01-22 at 15:25 -0800, Daniel Holbert wrote:
> Hi cairo folks,
> 
> As a fun itch to scratch, I've been fixing incorrect uses of the 
> contraction "it's" in comments within the mozilla source tree (tracked 
> in https://bugzilla.mozilla.org/show_bug.cgi?id=458167 ), and I ran 
> across 6 instances of this typo in mozilla's snapshot of cairo.
> 
> The attached patch fixes these typos in cairo -- per Vlad's suggestion, 
> I'm sending this patch upstream to you guys, in the hopes that you'll 
> incorporate it in future releases. :)

Applied, thank you. Those 6 are just the tip of the iceberg when it
comes to spelling corrections within the tree. Feel free to go mad. ;-)
-ickle