unikernels/linux: remove always-true conditional in firecracker block

[BRGOVIND]

Fixes the redundant conditional inside MonitorBlockCli() in
pkg/unikontainers/unikernels/linux.go.

What

The case "firecracker": arm of the switch already guarantees that
l.Monitor == "firecracker" is true. The inner if l.Monitor == "firecracker"
check can therefore never evaluate to false, making it dead code.

Before:

case "firecracker":
    for _, aBlock := range l.Blk {
        id := aBlock.ID
        if l.Monitor == "firecracker" {   // always true
            id = "FC" + aBlock.ID
        }
        blkArgs = append(blkArgs, types.MonitorBlockArgs{ID: id, Path: aBlock.Source})
    }

After:

case "firecracker":
    for _, aBlock := range l.Blk {
        blkArgs = append(blkArgs, types.MonitorBlockArgs{
            ID:   "FC" + aBlock.ID,
            Path: aBlock.Source,
        })
    }

Testing

Existing unit tests cover this path. No behaviour change — the "FC" prefix was
always applied; this just removes the dead branch.

Closes #747

[netlify]

✅ Deploy Preview for urunc canceled.

Name	Link
🔨 Latest commit	10e4ff5
🔍 Latest deploy log	https://app.netlify.com/projects/urunc/deploys/6a2f34b3408114000803c30d