Fix build with new independent stdext repository

Signed-off-by: Jon Ludlam <jonathan.ludlam@eu.citrix.com>
Ignore ENOENT when scanning the filesystem.

Files are created and destroyed by other processes, and this was
causing fatal errors.

Signed-off-by: Jon Ludlam <jonathan.ludlam@eu.citrix.com>
Merge pull request #2 from jonludlam/ignore-enoent

Ignore ENOENT when scanning the filesystem.
Merge pull request #3 from xapi-project/ea1254

ea-1254