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 <linmq006@gmail.com>
Reviewed-by: German Gomez <german.gomez@arm.com>
Tested-by: German Gomez <german.gomez@arm.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20211214011030.20200-1-linmq006@gmail.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

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)