[ALSA] echoaudio - Add barrier() to prevent compiler optimization

This patch adds a barrier() to prevent the compiler from
moving the read outside of the loop. It also fixes a comment.

Signed-off-by: Giuliano Pochini <pochini@shiny.it>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
diff --git a/sound/pci/echoaudio/echoaudio_dsp.c b/sound/pci/echoaudio/echoaudio_dsp.c
index 42afa83..e6c1007 100644
--- a/sound/pci/echoaudio/echoaudio_dsp.c
+++ b/sound/pci/echoaudio/echoaudio_dsp.c
@@ -43,11 +43,11 @@
 {
 	int i;
 
-	/* Wait up to 10ms for the handshake from the DSP */
+	/* Wait up to 20ms for the handshake from the DSP */
 	for (i = 0; i < HANDSHAKE_TIMEOUT; i++) {
 		/* Look for the handshake value */
+		barrier();
 		if (chip->comm_page->handshake) {
-			/*if (i)  DE_ACT(("Handshake time: %d\n", i));*/
 			return 0;
 		}
 		udelay(1);