perf expr: Fix return value of ids__new()

callers of ids__new() function only do NULL checking for the return
value. ids__new() calles hashmap__new(), which may return
ERR_PTR(-ENOMEM).

Instead of changing the checking one-by-one return NULL instead of
ERR_PTR(-ENOMEM) to keep it consistent.

Signed-off-by: Miaoqian Lin <[email protected]>
Reviewed-by: German Gomez <[email protected]>
Tested-by: German Gomez <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Author: Yuuoniy

tools/perf/util/expr.c

@@ -66,7 +66,12 @@ static bool key_equal(const void *key1, const void *key2,
 
 struct hashmap *ids__new(void)
 {
-	return hashmap__new(key_hash, key_equal, NULL);
+	struct hashmap *hash;
+
+	hash = hashmap__new(key_hash, key_equal, NULL);
+	if (IS_ERR(hash))
+		return NULL;
+	return hash;
 }
 
 void ids__free(struct hashmap *ids)