storagecommands: Extended I2C bus size to 16-bit

The entity-manager and phosphor-host-ipmid changed the D-Bus signature
of the I2C bus number variable from 8-bit to 16-bit.

This commit extented bus size to 16-bit to fix signature mismatch.

Signed-off-by: Potin Lai <potin.lai@quantatw.com>
Change-Id: I37d229bc19b59817ce39ac22d81ef8776feaf8cc
1 file changed