Fix crash in CPDFSDK_Annot::OnLButtonUp().

In https://pdfium-review.googlesource.com/92331, a copy + paste error is
passing the wrong annotation to CPDFSDK_Annot::OnLButtonUp() and causing
a nullptr dereference.

Bug: chromium:1315171
Change-Id: I6eb8c659431108d7d7217ddb02d880292142c06e
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/92510
Reviewed-by: Nigi <nigi@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
diff --git a/fpdfsdk/cpdfsdk_pageview.cpp b/fpdfsdk/cpdfsdk_pageview.cpp
index a41f296..b803f1c 100644
--- a/fpdfsdk/cpdfsdk_pageview.cpp
+++ b/fpdfsdk/cpdfsdk_pageview.cpp
@@ -349,7 +349,7 @@
   ObservedPtr<CPDFSDK_Annot> pFocusAnnot(GetFocusAnnot());
   if (pFocusAnnot && pFocusAnnot != pFXAnnot) {
     // Last focus Annot gets a chance to handle the event.
-    if (CPDFSDK_Annot::OnLButtonUp(pFXAnnot, nFlags, point))
+    if (CPDFSDK_Annot::OnLButtonUp(pFocusAnnot, nFlags, point))
       return true;
   }
   return pFXAnnot && CPDFSDK_Annot::OnLButtonUp(pFXAnnot, nFlags, point);