[IA64] spelling fixes: arch/ia64/

Spelling and apostrophe fixes in arch/ia64/.

Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/arch/ia64/mm/discontig.c b/arch/ia64/mm/discontig.c
index 38085ac..0dbf0e8 100644
--- a/arch/ia64/mm/discontig.c
+++ b/arch/ia64/mm/discontig.c
@@ -317,7 +317,7 @@
 	 * node_online_map is not set for hot-added nodes at this time,
 	 * because we are halfway through initialization of the new node's
 	 * structures.  If for_each_online_node() is used, a new node's
-	 * pg_data_ptrs will be not initialized. Insted of using it,
+	 * pg_data_ptrs will be not initialized. Instead of using it,
 	 * pgdat_list[] is checked.
 	 */
 	for_each_node(node) {