Fix another typo in BUILD.gn

TBR=thestig@chromium.org

Review URL: https://codereview.chromium.org/1438253004 .
diff --git a/BUILD.gn b/BUILD.gn
index 5b5a1b1..ec16d1b 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -748,7 +748,7 @@
     "core/src/fpdfapi/fpdf_page/fpdf_page_func_embeddertest.cpp",
     "core/src/fpdfapi/fpdf_parser/fpdf_parser_decode_embeddertest.cpp",
     "core/src/fpdfapi/fpdf_parser/fpdf_parser_parser_embeddertest.cpp",
-    "core/src/fpdfapi/fpdf_render/fpdf_render_load_image_embeddertest.cpp",
+    "core/src/fpdfapi/fpdf_render/fpdf_render_loadimage_embeddertest.cpp",
     "core/src/fpdfapi/fpdf_render/fpdf_render_pattern_embeddertest.cpp",
     "fpdfsdk/src/fpdf_dataavail_embeddertest.cpp",
     "fpdfsdk/src/fpdfdoc_embeddertest.cpp",