Staging: speakup: Remove unused variable

This patch removes variable that was used to store only the return value of a function call.

The issue was detected and resolved using the following coccinelle script:

@@
expression ret;
identifier f;
@@

 -ret =
 +return
    f(...);
 -return ret;
Signed-off-by: Haneen Mohammed <hamohammed.sa@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/speakup/kobjects.c

@@ -840,12 +840,10 @@ static ssize_t message_show(struct kobject *kobj,
 static ssize_t message_store(struct kobject *kobj, struct kobj_attribute *attr,
 	const char *buf, size_t count)
 {
-	ssize_t retval = 0;
 	struct msg_group_t *group = spk_find_msg_group(attr->attr.name);
 
 	BUG_ON(!group);
-	retval = message_store_helper(buf, count, group);
-	return retval;
+	return message_store_helper(buf, count, group);
 }
 
 /*