[libgnome-volume-control/gbsneto/unnecessary-warnings] mixer-control: Remove unnecessary instance checks

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 2a7a100a132eeb77a53fc0a20d86282e96d6c668
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Sat Jun 15 21:26:44 2019 -0300

    mixer-control: Remove unnecessary instance checks
    
    gvc_mixer_control_get_vol_max_norm() and gvc_mixer_control_get_vol_max_amplified()
    do not access any of the instance variables. In GNOME Settings, we even
    pass NULL to these functions. So checking the instance is not necessary.
    
    In fact, this is causing instance check failures in GNOME Settings, and
    the entire Sound panel is broken since those functions are returning zero.
    
    The reason that only the checks are being dropped, and not the parameter
    entirely, is to preserve API compatibility.

 gvc-mixer-control.c | 2 --
 1 file changed, 2 deletions(-)
---
diff --git a/gvc-mixer-control.c b/gvc-mixer-control.c
index c611a41..051f6ad 100644
--- a/gvc-mixer-control.c
+++ b/gvc-mixer-control.c
@@ -3744,13 +3744,11 @@ gvc_mixer_control_new (const char *name)
 gdouble
 gvc_mixer_control_get_vol_max_norm (GvcMixerControl *control)
 {
-       g_return_val_if_fail (GVC_IS_MIXER_CONTROL (control), 0);
        return (gdouble) PA_VOLUME_NORM;
 }
 
 gdouble
 gvc_mixer_control_get_vol_max_amplified (GvcMixerControl *control)
 {
-       g_return_val_if_fail (GVC_IS_MIXER_CONTROL (control), 0);
        return (gdouble) PA_VOLUME_UI_MAX;
 }