when IFS uses UNICODE , allocate memory as twice

if ifs uses unicode, i have to alloc twice memory

example

when ifs_strlen return 10 ;

it is really 20 byte;

so
TCHAR ifs_path;

len=strlen(path);

len = len << 2; // twice

ifs_path = ifs_malloc(len);

strncpy(ifs_path,L"mfm",sizeof(L"mfm"));
ifs_path = ifs_path+sizeof(L"mfm")); // increase
strcpy(ifs_path,path);