tpm: Disable TPM on tpm2_create_primary() failure

The earlier bug fix misplaced the error-label when dealing with the
tpm2_create_primary() return value, which the original completely ignored.

Cc: stable@vger.kernel.org
Reported-by: Christoph Anton Mitterer <calestyo@scientia.org>
Closes: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1087331


Fixes: cc7d8594 ("tpm: Rollback tpm2_load_null()")
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>