Fix NetBSD driver compile error and OSS link error.

configure.ac

@@ -193,6 +193,9 @@ netbsd*)
     AC_DEFINE(SOUND_NETBSD, 1, [ ])
     AM_CONDITIONAL([SOUND_NETBSD], [true])
   fi
+  if test "${ac_cv_header_sys_soundcard_h}" = "yes"; then
+    AC_CHECK_LIB(ossaudio, _oss_ioctl)
+  fi
   ;;
 solaris*)
   if test "${ac_cv_header_sys_audioio_h}" = "yes"; then

src/sound_netbsd.c

@@ -101,7 +101,7 @@ static void play(void *b, int i)
 	while (i) {
 		if ((j = write(audio_fd, b, i)) > 0) {
 			i -= j;
-			(char *)b += j;
+			b = (char *)b + j;
 		} else
 			break;
 	}