Fix use of an uninitialised CFX_Widestring in AFNumber_Keystroke.

BUG=611352
R=thestig@chromium.org

Review-Url: https://codereview.chromium.org/1977613002
diff --git a/fpdfsdk/javascript/PublicMethods.cpp b/fpdfsdk/javascript/PublicMethods.cpp
index 2b14b77..fa7b5d4 100644
--- a/fpdfsdk/javascript/PublicMethods.cpp
+++ b/fpdfsdk/javascript/PublicMethods.cpp
@@ -903,11 +903,10 @@
   CFX_WideString wstrValue = val;
 
   if (pEvent->WillCommit()) {
-    CFX_WideString wstrValue = StrTrim(wstrValue);
-    if (wstrValue.IsEmpty())
+    CFX_WideString swTemp = StrTrim(wstrValue);
+    if (swTemp.IsEmpty())
       return TRUE;
 
-    CFX_WideString swTemp = wstrValue;
     swTemp.Replace(L",", L".");
     if (!IsNumber(swTemp.c_str())) {
       pEvent->Rc() = FALSE;