staging: echo: fix a typo ("overflow")

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/staging/echo/echo.c b/drivers/staging/echo/echo.c
index 58c4e90..3c188d5 100644
--- a/drivers/staging/echo/echo.c
+++ b/drivers/staging/echo/echo.c
@@ -544,7 +544,7 @@
 				 * Just random numbers rolled off very vaguely
 				 * Hoth-like.  DR: This noise doesn't sound
 				 * quite right to me - I suspect there are some
-				 * overlfow issues in the filtering as it's too
+				 * overflow issues in the filtering as it's too
 				 * "crackly".
 				 * TODO: debug this, maybe just play noise at
 				 * high level or look at spectrum.