video: fbdev: omapfb: Fix set but not used warnings in hdmi*_core

Fix a few W=1 warnings about unused assignments.
Drop the unused error code.

v2:
  - Subject updated (Lee)
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Qilong Zhang <zhangqilong3@huawei.com>
Cc: "Alexander A. Klimov" <grandmaster@al2klimov.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Lee Jones <lee.jones@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20201206190247.1861316-4-sam@ravnborg.org

drivers/video/fbdev/omap2/omapfb/dss/hdmi4_core.c

@@ -679,7 +679,7 @@ int hdmi4_audio_config(struct hdmi_core_data *core, struct hdmi_wp_data *wp,
 	struct hdmi_audio_format audio_format;
 	struct hdmi_audio_dma audio_dma;
 	struct hdmi_core_audio_config acore;
-	int err, n, cts, channel_count;
+	int n, cts, channel_count;
 	unsigned int fs_nr;
 	bool word_length_16b = false;
 
@@ -741,7 +741,7 @@ int hdmi4_audio_config(struct hdmi_core_data *core, struct hdmi_wp_data *wp,
 		return -EINVAL;
 	}
 
-	err = hdmi_compute_acr(pclk, fs_nr, &n, &cts);
+	hdmi_compute_acr(pclk, fs_nr, &n, &cts);
 
 	/* Audio clock regeneration settings */
 	acore.n = n;

drivers/video/fbdev/omap2/omapfb/dss/hdmi5_core.c

@@ -790,7 +790,7 @@ int hdmi5_audio_config(struct hdmi_core_data *core, struct hdmi_wp_data *wp,
 	struct hdmi_audio_format audio_format;
 	struct hdmi_audio_dma audio_dma;
 	struct hdmi_core_audio_config core_cfg;
-	int err, n, cts, channel_count;
+	int n, cts, channel_count;
 	unsigned int fs_nr;
 	bool word_length_16b = false;
 
@@ -833,7 +833,7 @@ int hdmi5_audio_config(struct hdmi_core_data *core, struct hdmi_wp_data *wp,
 		return -EINVAL;
 	}
 
-	err = hdmi_compute_acr(pclk, fs_nr, &n, &cts);
+	hdmi_compute_acr(pclk, fs_nr, &n, &cts);
 	core_cfg.n = n;
 	core_cfg.cts = cts;