misc: fastrpc: Fix an incomplete memory release in fastrpc_rpmsg_probe()

fastrpc_channel_ctx is not freed if misc_register() fails, this would
lead to a memory leak. Fix this leak by adding kfree in misc_register()
error path.

Fixes: 278d56f970ae ("misc: fastrpc: Reference count channel context")
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20200511162722.2552-1-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index e3e085e..9065d3e 100644
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -1613,8 +1613,10 @@ static int fastrpc_rpmsg_probe(struct rpmsg_device *rpdev)
 					    domains[domain_id]);
 	data->miscdev.fops = &fastrpc_fops;
 	err = misc_register(&data->miscdev);
-	if (err)
+	if (err) {
+		kfree(data);
 		return err;
+	}
 
 	kref_init(&data->refcount);