docs: Fixed syntax error in makedev-syntax example.

In the makedev syntax documentation, one of the examples lacks the "mode"
value.  This patch fixes that example.

Signed-off-by: Alan Yaniger <alan@tkos.co.il>
Acked-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

docs/manual/makedev-syntax.txt

@@ -44,7 +44,7 @@ this syntax, you will need to write:
 ----
 /usr/bin/foo f 755 0 0 - - - - -
 /usr/bin/bar f 755 root root - - - - -
-/data/buz f buz-user buz-group - - - - -
+/data/buz f 644 buz-user buz-group - - - - -
 ----
 
 Alternatively, if you want to change owner/permission of a directory