Fix a bad memset() in FPDFTextEmbedderTest.

Found by g++ 8.

Change-Id: I3cd11677efd647f6de6a4f120c292e7dffaa3193
Reviewed-on: https://pdfium-review.googlesource.com/c/48711
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

fpdfsdk/fpdf_text_embeddertest.cpp

diff --git a/fpdfsdk/fpdf_text_embeddertest.cpp b/fpdfsdk/fpdf_text_embeddertest.cpp
index 109bbfd..4b3bcc5 100644
--- a/fpdfsdk/fpdf_text_embeddertest.cpp
+++ b/fpdfsdk/fpdf_text_embeddertest.cpp
@@ -452,7 +452,7 @@
   unsigned short buffer[128];
   for (int i = 0; i < kNumLinks; i++) {
     const size_t expected_len = strlen(kExpectedUrls[i]) + 1;
-    memset(buffer, 0, FX_ArraySize(buffer));
+    memset(buffer, 0, sizeof(buffer));
     EXPECT_EQ(static_cast<int>(expected_len),
               FPDFLink_GetURL(pagelink, i, nullptr, 0));
     EXPECT_EQ(static_cast<int>(expected_len),