Fix cut/paste error in fx_extension_unittest.cpp

Incorrect length for string constant in FXSYS_wcstof test.

Change-Id: I4b65277513236ab98b071b044a79ac7245c6ef97
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/117330
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Thomas Sepez <tsepez@google.com>
Commit-Queue: Thomas Sepez <tsepez@google.com>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Auto-Submit: Tom Sepez <tsepez@chromium.org>
diff --git a/core/fxcrt/fx_extension_unittest.cpp b/core/fxcrt/fx_extension_unittest.cpp
index 8a4b012..e59070c 100644
--- a/core/fxcrt/fx_extension_unittest.cpp
+++ b/core/fxcrt/fx_extension_unittest.cpp
@@ -155,7 +155,7 @@
   EXPECT_EQ(0u, used_len);
 
   used_len = 0;
-  EXPECT_FLOAT_EQ(0.0f, FXSYS_wcstof(L"1.234E-128", 21, &used_len));
+  EXPECT_FLOAT_EQ(0.0f, FXSYS_wcstof(L"1.234E-128", 10, &used_len));
   EXPECT_EQ(0u, used_len);
 
   // TODO(dsinclair): This should round as per IEEE 64-bit values.