Fix some nits in FPDFDOC_InitFormFillEnvironment().

Change-Id: Ia02283c7e59bf80f6461a0f69454a469cd95ceae
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/58370
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
diff --git a/fpdfsdk/fpdf_formfill.cpp b/fpdfsdk/fpdf_formfill.cpp
index 5293f05..935191c 100644
--- a/fpdfsdk/fpdf_formfill.cpp
+++ b/fpdfsdk/fpdf_formfill.cpp
@@ -316,9 +316,9 @@
 FPDFDOC_InitFormFillEnvironment(FPDF_DOCUMENT document,
                                 FPDF_FORMFILLINFO* formInfo) {
 #ifdef PDF_ENABLE_XFA
-  const int kRequiredVersion = 2;
+  constexpr int kRequiredVersion = 2;
 #else   // PDF_ENABLE_XFA
-  const int kRequiredVersion = 1;
+  constexpr int kRequiredVersion = 1;
 #endif  // PDF_ENABLE_XFA
   if (!formInfo || formInfo->version != kRequiredVersion)
     return nullptr;
@@ -338,8 +338,8 @@
   }
 #endif
 
-  auto pFormFillEnv = pdfium::MakeUnique<CPDFSDK_FormFillEnvironment>(
-      CPDFDocumentFromFPDFDocument(document), formInfo);
+  auto pFormFillEnv =
+      pdfium::MakeUnique<CPDFSDK_FormFillEnvironment>(pDocument, formInfo);
 
 #ifdef PDF_ENABLE_XFA
   if (pContext)