qemu_namespace: Properly report new files

qemu_namespace: Properly report new files

Function qemuNamespaceMknodOne() is supposed to return 0 if the file did
not exist before this function.  If, however, the file existed, but was
removed and recreated by this function the @existed flag should be reset
to its proper state (false) because the function then behaves the same
way as if the file did not exist as it needed to be recreated.

So reset the @existed flag to properly reflect what happened.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>