raw-posix: Typo fix

Signed-off-by: Frediano Ziglio <freddy77@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block/raw-posix.c

diff --git a/block/raw-posix.c b/block/raw-posix.c
index 6672d31..6dd7086 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -587,7 +587,7 @@
 
     /*
      * If O_DIRECT is used the buffer needs to be aligned on a sector
-     * boundary.  Check if this is the case or telll the low-level
+     * boundary.  Check if this is the case or tell the low-level
      * driver that it needs to copy the buffer.
      */
     if (s->aligned_buf) {