Remove some pointless assignments to "".

Or change them to clear().

Change-Id: Ia9e3e1f0d74b948cec3f8df85d205f830ac9216c
Reviewed-on: https://pdfium-review.googlesource.com/19172
Reviewed-by: dsinclair <dsinclair@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
diff --git a/fxjs/cjs_global.cpp b/fxjs/cjs_global.cpp
index 0fef8d5..db63a4b 100644
--- a/fxjs/cjs_global.cpp
+++ b/fxjs/cjs_global.cpp
@@ -555,7 +555,7 @@
     if (pTemp->bDeleted || pTemp->nType != nType) {
       pTemp->dData = 0;
       pTemp->bData = 0;
-      pTemp->sData = "";
+      pTemp->sData.clear();
       pTemp->nType = nType;
     }
     pTemp->bDeleted = false;