[Patch] Fix return value in pthread_create

[Roland McGrath]

> If we are going to check for ENOMEM in pthread_create.c then
> allocatestack.c should be fixed to stop checking for the same
> condition.

I gave Jeff the benefit of the doubt and was too lazy to hunt down that
code.  If it's checked adequately there then there's no reason for the
change I made.  But since it's already in, and it has the translation in
one place instead of five, that plus your change seems ultimately better.
Go ahead and commit it if you don't find any problems.

The only potential caveat is that there is one path where we were changing
errno as well.  But since the other four paths don't do that, I guess it
doesn't matter what's in errno.


Thanks,
Roland