list-objects-filter-options: fix 'keword' typo in comment

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: chriscool

list-objects-filter-options.c

@@ -8,7 +8,7 @@
 #include "list-objects-filter-options.h"
 
 /*
- * Parse value of the argument to the "filter" keword.
+ * Parse value of the argument to the "filter" keyword.
  * On the command line this looks like:
  *       --filter=<arg>
  * and in the pack protocol as: