Use another vector for installed fonts in CFX_FontMapper

fpdfsdk/cfx_systemhandler.cpp

Index: fpdfsdk/cfx_systemhandler.cpp
diff --git a/fpdfsdk/cfx_systemhandler.cpp b/fpdfsdk/cfx_systemhandler.cpp
index adcc5bee566f2e2ba7bb542b6dbb0a4fbadb41e2..1f49e9e862ba5f33f512f4a193fe442e5fb0f886 100644
--- a/fpdfsdk/cfx_systemhandler.cpp
+++ b/fpdfsdk/cfx_systemhandler.cpp
@@ -102,8 +102,8 @@ bool CFX_SystemHandler::FindNativeTrueTypeFont(CFX_ByteString sFontFaceName) {
   if (pFontMapper->m_InstalledTTFonts.empty())
     pFontMapper->LoadInstalledFonts();
 
-  for (const auto& font : pFontMapper->m_InstalledTTFonts) {
-    if (font.Compare(sFontFaceName.AsStringC()))
+  for (const auto& it : pFontMapper->m_InstalledTTFonts) {
+    if (it.second.Compare(sFontFaceName.AsStringC()))
       return true;
   }
   return false;