treewide: move HostInterfaceMAC to a tracked duplicate var

This is required to not accidentally pull-in future qemu runfiles.

Change-Id: I6098900d047f21096c0b1f6b2176d2480f8e6ab0
Reviewed-on: https://review.monogon.dev/c/monogon/+/4054
Tested-by: Jenkins CI
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
diff --git a/osbase/test/qemu/launch.go b/osbase/test/qemu/launch.go
index 52a1492..1b063de 100644
--- a/osbase/test/qemu/launch.go
+++ b/osbase/test/qemu/launch.go
@@ -22,6 +22,12 @@
 	"source.monogon.dev/osbase/freeport"
 )
 
+var (
+	// HostInterfaceMAC is the MAC address the host SLIRP network interface has if it
+	// is not disabled (see DisableHostNetworkInterface in MicroVMOptions)
+	HostInterfaceMAC = net.HardwareAddr{0x02, 0x72, 0x82, 0xbf, 0xc3, 0x56}
+)
+
 type QemuValue map[string][]string
 
 // ToOption encodes structured data into a QEMU option. Example: "test", {"key1":
@@ -130,10 +136,6 @@
 	return fd1, fd2, nil
 }
 
-// HostInterfaceMAC is the MAC address the host SLIRP network interface has if it
-// is not disabled (see DisableHostNetworkInterface in MicroVMOptions)
-var HostInterfaceMAC = net.HardwareAddr{0x02, 0x72, 0x82, 0xbf, 0xc3, 0x56}
-
 // MicroVMOptions contains all options to start a MicroVM
 type MicroVMOptions struct {
 	// Name is a human-readable identifier to be used in debug output.