[ALSA] Remove zero-initialization of static variables

Removed zero-initializations of static variables.
A tiny optimization.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/core/info.c b/sound/core/info.c
index c8eeaea..10c1772 100644
--- a/sound/core/info.c
+++ b/sound/core/info.c
@@ -143,12 +143,12 @@
 
  */
 
-static struct proc_dir_entry *snd_proc_root = NULL;
-struct snd_info_entry *snd_seq_root = NULL;
+static struct proc_dir_entry *snd_proc_root;
+struct snd_info_entry *snd_seq_root;
 EXPORT_SYMBOL(snd_seq_root);
 
 #ifdef CONFIG_SND_OSSEMUL
-struct snd_info_entry *snd_oss_root = NULL;
+struct snd_info_entry *snd_oss_root;
 #endif
 
 static inline void snd_info_entry_prepare(struct proc_dir_entry *de)
@@ -972,7 +972,7 @@
 
  */
 
-static struct snd_info_entry *snd_info_version_entry = NULL;
+static struct snd_info_entry *snd_info_version_entry;
 
 static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
 {