PVS-Studio warning V512 for Fennec Media Project

typedef wchar_t letter;

letter name[30];

int Conv_EqualizerProc(HWND hwnd,UINT uMsg,
  WPARAM wParam,LPARAM lParam)
{
  ...
  memset(eqp.name, 0, 30);
  ...
}

This is what should have been written here: sizeof(latter) * 30

This suspicious code was found in Fennec Media Project project by PVS-Studio static code analyzer.
Warning message is:
V512 A call of the 'memset' function will lead to a buffer overflow or underflow. base windows.c 2892

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/