Remove .c_str() in CXFA_FMExpression::ToJavaScript()

The << operator already handles widestrings.

Change-Id: I0213248096f4a96100d761f1573fe1c5c318b0dc
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/86850
Auto-Submit: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>

xfa/fxfa/fm2js/cxfa_fmexpression.cpp

diff --git a/xfa/fxfa/fm2js/cxfa_fmexpression.cpp b/xfa/fxfa/fm2js/cxfa_fmexpression.cpp
index a080b46..6aac77f 100644
--- a/xfa/fxfa/fm2js/cxfa_fmexpression.cpp
+++ b/xfa/fxfa/fm2js/cxfa_fmexpression.cpp
@@ -384,7 +384,7 @@
   if (CXFA_IsTooBig(*js) || !depthManager.IsWithinMaxDepth())
     return false;
 
-  *js << "pfm_rt." << m_OpName.c_str() << "(";
+  *js << "pfm_rt." << m_OpName << "(";
   if (!m_pExp->ToJavaScript(js, ReturnType::kInferred))
     return false;
   *js << ")";