nvme: blank out authentication fabrics options if not configured

If the config option NVME_HOST_AUTH is not selected we should not
accept the corresponding fabrics options. This allows userspace
to detect if NVMe authentication has been enabled for the kernel.

Cc: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Fixes: f50fff73 ("nvme: implement In-Band authentication")
Signed-off-by: Hannes Reinecke <hare@suse.de>
Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

drivers/nvme/host/fabrics.c

@@ -667,8 +667,10 @@ static const match_table_t opt_tokens = {
 #endif
 	{ NVMF_OPT_FAIL_FAST_TMO,	"fast_io_fail_tmo=%d"	},
 	{ NVMF_OPT_DISCOVERY,		"discovery"		},
+#ifdef CONFIG_NVME_HOST_AUTH
 	{ NVMF_OPT_DHCHAP_SECRET,	"dhchap_secret=%s"	},
 	{ NVMF_OPT_DHCHAP_CTRL_SECRET,	"dhchap_ctrl_secret=%s"	},
+#endif
 #ifdef CONFIG_NVME_TCP_TLS
 	{ NVMF_OPT_TLS,			"tls"			},
 #endif