patch 8.2.5107: some callers of rettv_list_alloc() check for not OK

Problem:    Some callers of rettv_list_alloc() check for not OK. (Christ van
            Willegen)
Solution:   Use "==" instead of "!=" when checking the return value.
diff --git a/src/map.c b/src/map.c
index 80ac8aa..9570285 100644
--- a/src/map.c
+++ b/src/map.c
@@ -2379,7 +2379,7 @@
 	}
 
     }
-    else if (rettv_dict_alloc(rettv) != FAIL && rhs != NULL)
+    else if (rettv_dict_alloc(rettv) == OK && rhs != NULL)
 	mapblock2dict(mp, rettv->vval.v_dict,
 			  did_simplify ? keys_simplified : NULL,
 			  buffer_local, abbr);
@@ -2409,7 +2409,7 @@
     if (argvars[0].v_type != VAR_UNKNOWN)
 	abbr = tv_get_bool(&argvars[0]);
 
-    if (rettv_list_alloc(rettv) != OK)
+    if (rettv_list_alloc(rettv) == FAIL)
 	return;
 
     validate_maphash();