Clarify that ErrorInfoValue is a NotComparableSkyValue because we don't expect equality, not because there's no implementation.

PiperOrigin-RevId: 201191262
diff --git a/src/main/java/com/google/devtools/build/skyframe/ValueWithMetadata.java b/src/main/java/com/google/devtools/build/skyframe/ValueWithMetadata.java
index a0c5108..8254f2e 100644
--- a/src/main/java/com/google/devtools/build/skyframe/ValueWithMetadata.java
+++ b/src/main/java/com/google/devtools/build/skyframe/ValueWithMetadata.java
@@ -179,10 +179,10 @@
   /**
    * Implementation of {@link ValueWithMetadata} for the error case.
    *
-   * ErorInfo does not override equals(), so it may as well be marked NotComparableSkyValue.
+   * <p>Mark NotComparableSkyValue because it's unlikely that re-evaluation gives the same error.
    */
   private static final class ErrorInfoValue extends ValueWithMetadata
-          implements NotComparableSkyValue {
+      implements NotComparableSkyValue {
 
     private final ErrorInfo errorInfo;
     private final NestedSet<TaggedEvents> transitiveEvents;