PVS-Studio warning V579 for Dolphin

u32 Flatten(..., BlockStats *st, ...)
{
  ...
  memset(st, 0, sizeof(st));
  ...
}

This suspicious code was found in Dolphin project by PVS-Studio static code analyzer.
Warning message is:
V579 The memset function receives the pointer and its size as arguments. It is possibly a mistake. Inspect the third argument. Core ppcanalyst.cpp 302

PVS-Studio is a static analyzer for detecting bugs in the source code of applications written in C, C++, C++11, C++/CX. Site: http://www.viva64.com/en/pvs-studio/