Don't spam console with "failed to write to tap" messages

[larsks]

A common first experience with firecracker (see e.g. #746) is to start a new virtual machine and immediately start getting spammed with messages like:

2024-06-21T22:10:18.189726925 [anonymous-instance:main] Failed to write
to tap: Os { code: 5, kind: Uncategorized, message: "Input/output
error" }

This happens because firecracker will create the tap device if it doesn't already exist, and unlike most vmms it will not configure the device up in this case.

All that means that this is both a common and an expected situation and does not require this level of notification.

Signed-off-by: Lars Kellogg-Stedman [email protected]