NFC: st21nfca: Fix incorrect byte stuffing revocation

Byte stuffing was not correctly removed after a i2c read operation.
This was causing improper crc calculation when byte stuffing was
applied to more than 1 byte.

Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>