Changes

esim.bsp: Fix a bug in demac_only_one()

When de-MAC-ing at the recipient side, we must increment the cipher(!)
block number even if no ciphering is done at all.

We did this correctly for MAC (sender) case, but not on the de-MAC
(receiver) case.

Change-Id: I97993f9e8357b36401d435aaa15558d1c7e411eb