kernel: media: dvb-usb: az6027: fix null-ptr-deref in az6027_i2c_xfer()

In the Linux kernel, the following vulnerability has been resolved: media: dvb-usb: az6027: fix null-ptr-deref in az6027i2cxfer Wei Chen reports a kernel bug as blew: general protection fault, probably for non-canonical address KASAN: null-ptr-deref in range 0x0000000000000010-0x0000000000000017...