extcon: cros-ec: Fix a potential NULL pointer dereference

Return -ENOMEM in case of memory allocation failure. This avoids a NULL
pointer dereference.

Fixes: c69831666109 ("extcon: cros-ec: Add extcon-cros-ec driver to support display out")
Signed-off-by: Christophe JAILLET <[e-mail]>
Signed-off-by: Chanwoo Choi <[e-mail]>

drivers/extcon/extcon-usbc-cros-ec.c

···
 	int ret;
 
 	msg = kzalloc(sizeof(*msg) + max(outsize, insize), GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
 
 	msg->version = version;
 	msg->command = command;