Documentation: fix reference to a for-each-ref option

... to match the synopsis section

Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-for-each-ref.txt

@@ -16,7 +16,7 @@ DESCRIPTION
 
 Iterate over all refs that match `<pattern>` and show them
 according to the given `<format>`, after sorting them according
-to the given set of `<key>`.  If `<max>` is given, stop after
+to the given set of `<key>`.  If `<count>` is given, stop after
 showing that many refs.  The interpolated values in `<format>`
 can optionally be quoted as string literals in the specified
 host language allowing their direct evaluation in that language.