Libraries updates and cleanup

* Updating common/lib
 * Updating lib/csu
 * Updating lib/libc
 * Updating libexec/ld.elf_so
 * Corrected test on __minix in featuretest to actually follow the
   meaning of the comment.
 * Cleaned up _REENTRANT-related defintions.
 * Disabled -D_REENTRANT for libfetch
 * Removing some unneeded __NBSD_LIBC defines and tests

Change-Id: Ic1394baef74d11b9f86b312f5ff4bbc3cbf72ce2

drivers/audio/es1371/AC97.c

@@ -341,7 +341,7 @@ static void set_nice_volume(void) {
 
 
 static int get_volume(u8_t *left, u8_t *right, int cmd) {
-	u16_t value;
+	u16_t value = 0;
 
 	AC97_read_unsynced(dev, (u16_t)cmd, &value);
 

drivers/tty/arch/i386/console.c

@@ -154,7 +154,7 @@ int try;
  */
 
   int count;
-  int result;
+  int result = OK;
   register char *tbuf;
   char buf[64];
   console_t *cons = tp->tty_priv;