security: Don't remember labels for TPM

security: Don't remember labels for TPM

https://bugzilla.redhat.com/show_bug.cgi?id=1755803

The /dev/tpmN file can be opened only once, as implemented in
drivers/char/tpm/tpm-dev.c:tpm_open() from the kernel's tree. Any
other attempt to open the file fails. And since we're opening the
file ourselves and passing the FD to qemu we will not succeed
opening the file again when locking it for seclabel remembering.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>