ALSA: hda: patch_realtek: fix empty macro usage in if block

GCC reports the following warning with W=1

sound/pci/hda/patch_realtek.c: In function ‘alc269_suspend’:
sound/pci/hda/patch_realtek.c:3616:29: warning: suggest braces around
empty body in an ‘if’ statement [-Wempty-body]
 3616 |   alc5505_dsp_suspend(codec);
      |                             ^

sound/pci/hda/patch_realtek.c: In function ‘alc269_resume’:
sound/pci/hda/patch_realtek.c:3651:28: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]
 3651 |   alc5505_dsp_resume(codec);
      |                            ^

This is a classic macro problem and can indeed lead to bad program
flows.

Fix by using the usual "do { } while (0)" pattern
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200111214736.3002-2-pierre-louis.bossart@linux.intel.comSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/hda/patch_realtek.c

@@ -3601,8 +3601,8 @@ static void alc5505_dsp_init(struct hda_codec *codec)
 }
 
 #ifdef HALT_REALTEK_ALC5505
-#define alc5505_dsp_suspend(codec)	/* NOP */
-#define alc5505_dsp_resume(codec)	/* NOP */
+#define alc5505_dsp_suspend(codec)	do { } while (0) /* NOP */
+#define alc5505_dsp_resume(codec)	do { } while (0) /* NOP */
 #else
 #define alc5505_dsp_suspend(codec)	alc5505_dsp_halt(codec)
 #define alc5505_dsp_resume(codec)	alc5505_dsp_back_from_halt(codec)