CVE-2023-54266 media: dvb-usb: m920x: Fix a potential memory leak in m920x_i2c_xfer()

In the Linux kernel, the following vulnerability has been resolved: media: dvb-usb: m920x: Fix a potential memory leak in m920xi2cxfer 'read' is freed when it is known to be NULL, but not when a read error occurs. Revert the logic to avoid a small leak, should a m920xread call fail...