ionic: Remove redundant null pointer checks in ionic_debugfs_add_qcq()

Since the debugfs_create_dir() never returns a null pointer, checking
the return value for a null pointer is redundant, and using IS_ERR is
safe enough.
Signed-off-by: Li Zetao <lizetao1@huawei.com>
Link: https://patch.msgid.link/20240903143149.2004530-1-lizetao1@huawei.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/pensando/ionic/ionic_debugfs.c

@@ -123,7 +123,7 @@ void ionic_debugfs_add_qcq(struct ionic_lif *lif, struct ionic_qcq *qcq)
 	struct ionic_cq *cq = &qcq->cq;
 
 	qcq_dentry = debugfs_create_dir(q->name, lif->dentry);
-	if (IS_ERR_OR_NULL(qcq_dentry))
+	if (IS_ERR(qcq_dentry))
 		return;
 	qcq->dentry = qcq_dentry;