Revert "Patchwork [v5,2/3] block: Add API for urgent request handling"

This reverts commit 8d416e88482b48995ba38bf47aa7ba3ae2192e19.
Revert "Patchwork [v5,1/3] block: Add support for reinsert a dispatched req"

This reverts commit 64f089d4090d8fcca303ad1865dc6d298e4b37a2.