- fixed allocation size when constructing a string from a file system entry.

The internal allocator already added space for the terminazing \0, so the string's size was one character too large.

src/common/filesystem/filesystem.cpp

@@ -1612,7 +1612,7 @@ FString::FString (ELumpNum lumpnum)
 {
 	auto lumpr = fileSystem.OpenFileReader((int)lumpnum);
 	auto size = lumpr.GetLength();
-	AllocBuffer (1 + size);
+	AllocBuffer(size);
 	auto numread = lumpr.Read(&Chars[0], size);
 	Chars[size] = '\0';