ApprovalsUtil: Pass correct committerId to canSee

Accidentally passed authorId after checking that committerId is not
null, which can lead to NPE if authorId is null.

Change-Id: I178257cd1bc278e7d56c073c4cc6bcbc35ac294c
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/ApprovalsUtil.java b/gerrit-server/src/main/java/com/google/gerrit/server/ApprovalsUtil.java
index 5a5d16c..5c0723a 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/ApprovalsUtil.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/ApprovalsUtil.java
@@ -221,7 +221,7 @@
       need.add(authorId);
     }
 
-    if (committerId != null && canSee(db, update.getNotes(), authorId)) {
+    if (committerId != null && canSee(db, update.getNotes(), committerId)) {
       need.add(committerId);
     }
     need.remove(change.getOwner());