i2c: mlxbf: prevent stack overflow in mlxbf_i2c_smbus_start_transaction()

In the Linux kernel, the following vulnerability has been resolved: i2c: mlxbf: prevent stack overflow in mlxbf_i2c_smbus_start_transaction() memcpy() is called in a loop while 'operation->length' upper bound is not checked and 'data_idx' also increments.