char/tpm: Fix unitialized usage of data buffer

This patch fixes information leakage to the userspace by initializing
the data buffer to zero.

Reported-by: Peter Huewe <huewe.external@infineon.com>
Signed-off-by: Peter Huewe <huewe.external@infineon.com>
Signed-off-by: Marcel Selhorst <m.selhorst@sirrix.com>
[ Also removed the silly "* sizeof(u8)".  If that isn't 1, we have way
  deeper problems than a simple multiplication can fix.   - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
void tpm_dev_vendor_release(struct tpm_chip *chip)
{
	if (chip->vendor.release)
		chip->vendor.release(chip->dev);

	clear_bit(chip->dev_num, dev_mask);
	kfree(chip->vendor.miscdev.name);
}

void tpm_dev_vendor_release(struct tpm_chip *chip)
{
	if (chip->vendor.release)
		chip->vendor.release(chip->dev);

	clear_bit(chip->dev_num, dev_mask);
	kfree(chip->vendor.miscdev.name);
}
