That's exactly what it is. The third parameter to memcmp is the length of the buffers to be compared - "G847MC6JZ5", the string being compared, has a length of 11 characters (including the null terminator, which is a little odd). 11 is B in hex, and is stored as an unsigned Long Long, so the representation in the disassembler is 0xBuLL.

And that string is the Blizzard identifier: https://www.virustotal.com/en/file/bdfd2017fb776b52a4604928e...