CVE-2024-26632 block: Fix iterating over an empty bio with bio_for_each_folio_all

In the Linux kernel, the following vulnerability has been resolved: block: Fix iterating over an empty bio with bioforeachfolioall If the bio contains no data, biofirstfolio calls pagefolio on a NULL pointer and oopses. Move the test that we've reached the end of the bio from bionextfolio to...