chore: Fill placeholder for PR number of virtio PCI transport fix

The change was made privately, so the PR number wasn't available.

Signed-off-by: Takahiro Itazuri <itazur@amazon.com>

Author: zulinx86

CHANGELOG.md

@@ -15,14 +15,14 @@ and this project adheres to
   a descriptor chain that caused Firecracker to allocate more host memory than
   the guest actually provided, potentially leading to excessive host memory
   consumption.
-- [#XXXX](https://github.com/firecracker-microvm/firecracker/pull/XXXX): Enforce
+- [#5818](https://github.com/firecracker-microvm/firecracker/pull/5818): Enforce
   the virtio device initialization sequence in the PCI transport, matching the
   existing MMIO transport behavior. The PCI transport now validates device
   status transitions, rejects queue configuration writes outside the FEATURES_OK
   to DRIVER_OK window, rejects feature negotiation outside the DRIVER state,
   blocks re-initialization after a failed reset, and sets DEVICE_NEEDS_RESET
   when device activation fails.
-- [#XXXX](https://github.com/firecracker-microvm/firecracker/pull/XXXX): Reject
+- [#5818](https://github.com/firecracker-microvm/firecracker/pull/5818): Reject
   device status writes that clear previously set bits in the MMIO transport,
   except for reset.
 - [#5780](https://github.com/firecracker-microvm/firecracker/pull/5780): Fixed