Bluetooth: Fix faulty expression for minimum encryption key size check

Fix minimum encryption key size check so that HCI_MIN_ENC_KEY_SIZE is
also allowed as stated in the comment.

This bug caused connection problems with devices having maximum
encryption key size of 7 octets (56-bit).

Fixes: 693cd8ce3f88 ("Bluetooth: Fix regression with minimum encryption key size alignment")
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203997
Signed-off-by: Matias Karhumaa <matias.karhumaa@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
