spelling fixes: lib/

Spelling fix in lib/.
Signed-off-by: NSimon Arlott <simon@fire.lp0.eu>
Signed-off-by: NAdrian Bunk <bunk@kernel.org>

lib/kernel_lock.c

@@ -2,7 +2,7 @@
  * lib/kernel_lock.c
  *
  * This is the traditional BKL - big kernel lock. Largely
- * relegated to obsolescense, but used by various less
+ * relegated to obsolescence, but used by various less
  * important (or lazy) subsystems.
  */
 #include <linux/smp_lock.h>