Call CheckLinearizedFirstPage() when loading the first linearized page.

Otherwise CheckLinearizedFirstPage() has no other callers.

BUG=pdfium:330
R=jun_fang@foxitsoftware.com

Review URL: https://codereview.chromium.org/1543193002 .

core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp

diff --git a/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp b/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp
index 2a271f1..05f407b 100644
--- a/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp
+++ b/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp
@@ -4381,6 +4381,8 @@
 
   if (m_bLinearized) {
     if ((FX_DWORD)iPage == m_dwFirstPageNo) {
+      if (!CheckLinearizedFirstPage(iPage, pHints))
+        return DataNotAvailable;
       m_pagesLoadState.insert(iPage);
       return DataAvailable;
     }