Correct buffer length calculation in dumpSourceBytes (shader-slang#6593)

No functional change as overallocating was ok, but this was wrong

Co-authored-by: Yong He <yonghe@outlook.com>

Author: expipiplus1

source/core/slang-hex-dump-util.cpp

@@ -79,7 +79,7 @@ SlangResult HexDumpUtil::dumpSourceBytes(
 
         // each byte is output as "0xAA, "
         // Ends with '\n"
-        const size_t lineBytes = count * (4 + 1 + 1) * count + 1;
+        const size_t lineBytes = count * 6 + 1;
 
         char* startDst = writer->beginAppendBuffer(lineBytes);
         char* dst = startDst;