um: hostaudio: Do not propagate mixer parameter to kernel

This parameter is UML specific and is unknown to kernel. It should
not be propagated to kernel, otherwise it will trigger a warning and
be passed to user space as an environment option.

Signed-off-by: Tiwei Bie <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Johannes Berg <[e-mail]>

arch/um/drivers/hostaudio_kern.c

···
 
 static int set_mixer(char *name, int *add)
 {
+	*add = 0;
 	mixer = name;
 	return 0;
 }