ALSA: core: avoid -Wempty-body warnings

Building with 'make W=1' shows some warnings about empty function-style
macros:

sound/core/pcm_memory.c: In function 'preallocate_pages':
sound/core/pcm_memory.c:236:49: error: suggest braces around empty body in an 'if' statement [-Werror=empty-body]
  236 |                 preallocate_info_init(substream);

sound/core/seq_device.c: In function 'snd_seq_device_dev_register':
sound/core/seq_device.c:163:41: error: suggest braces around empty body in an 'if' statement [-Werror=empty-body]
  163 |                 queue_autoload_drivers();

Change them to empty inline functions, which are more robust here.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20210322103128.547199-1-arnd@kernel.orgSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/core/oss/pcm_oss.c

@@ -3069,8 +3069,12 @@ static void snd_pcm_oss_proc_done(struct snd_pcm *pcm)
 	}
 }
 #else /* !CONFIG_SND_VERBOSE_PROCFS */
-#define snd_pcm_oss_proc_init(pcm)
-#define snd_pcm_oss_proc_done(pcm)
+static inline void snd_pcm_oss_proc_init(struct snd_pcm *pcm)
+{
+}
+static inline void snd_pcm_oss_proc_done(struct snd_pcm *pcm)
+{
+}
 #endif /* CONFIG_SND_VERBOSE_PROCFS */
 
 /*

sound/core/pcm_memory.c

@@ -214,7 +214,9 @@ static inline void preallocate_info_init(struct snd_pcm_substream *substream)
 }
 
 #else /* !CONFIG_SND_VERBOSE_PROCFS */
-#define preallocate_info_init(s)
+static inline void preallocate_info_init(struct snd_pcm_substream *substream)
+{
+}
 #endif /* CONFIG_SND_VERBOSE_PROCFS */
 
 /*

sound/core/seq_device.c

@@ -133,10 +133,19 @@ void snd_seq_device_load_drivers(void)
 	flush_work(&autoload_work);
 }
 EXPORT_SYMBOL(snd_seq_device_load_drivers);
-#define cancel_autoload_drivers()	cancel_work_sync(&autoload_work)
+
+static inline void cancel_autoload_drivers(void)
+{
+	cancel_work_sync(&autoload_work);
+}
 #else
-#define queue_autoload_drivers() /* NOP */
-#define cancel_autoload_drivers() /* NOP */
+static inline void queue_autoload_drivers(void)
+{
+}
+
+static inline void cancel_autoload_drivers(void)
+{
+}
 #endif
 
 /*