patch 9.1.0772: some missing changes from v9.1.0771

Problem:  some missing changes from v9.1.0771
Solution: use correct highlighting attribute and adjust comments
          (glepnir)

closes: #15836

Signed-off-by: glepnir <glephunter@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/structs.h b/src/structs.h
index debc7df..da403ff 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -4474,7 +4474,7 @@
     char_u	*pum_info;		// extra info
     int		pum_score;		// fuzzy match score
     int		pum_idx;		// index of item before sorting by score
-    int		pum_user_abbr_hlattr;	// highlight attribute to combine with
+    int		pum_user_abbr_hlattr;	// highlight attribute for abbr
     int		pum_user_kind_hlattr;	// highlight attribute for kind
 } pumitem_T;