fxbarcode: include stdlib.h for abs

This is to fix
https://ci.chromium.org/ui/p/chromium/builders/try/win-libfuzzer-asan-rel/1987415/overview

Bug: 376278210
Change-Id: I5834e59bc6c56e4a77e0ea9c376aa1f34c2b5a98
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/125930
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Auto-Submit: Takuto Ikuta <tikuta@google.com>
diff --git a/fxbarcode/qrcode/BC_QRCoderMaskUtil.cpp b/fxbarcode/qrcode/BC_QRCoderMaskUtil.cpp
index a8cc5d9..a7695be 100644
--- a/fxbarcode/qrcode/BC_QRCoderMaskUtil.cpp
+++ b/fxbarcode/qrcode/BC_QRCoderMaskUtil.cpp
@@ -22,6 +22,8 @@
 
 #include "fxbarcode/qrcode/BC_QRCoderMaskUtil.h"
 
+#include <stdlib.h>
+
 #include "core/fxcrt/check.h"
 #include "core/fxcrt/notreached.h"
 #include "fxbarcode/common/BC_CommonByteMatrix.h"