Fix compatibility with older iouring
Fix compatibility with older iouring

Summary:
The fallback signature of makeProvidedBufferRing didn't match the main implementation, resulting in errors when building against older iouring.
Related: https://github.com/facebook/folly/issues/1832
It appears there are still other issues with older versions of iouring.

Reviewed By: DylanZA

Differential Revision: D38639544

fbshipit-source-id: b452ac71bbe0ec24d7dee9275cff7407bba056d8

facebook/folly,facebook/folly,facebook/folly,facebook/folly,facebook/folly