sdr: remove double called _from_data()
sdr: remove double called _from_data()

The constructor of the parent class (SdrCommon) already calls the
_from_data() method. We can remove this.

Fixes #101

Signed-off-by: Heiko Thiery <965a85d69f7aa0aa83bbdecf1b37e17133c01ac3@gmail.com>

kontron/python-ipmi