printk: fix global comment

Fix typo/spello.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

kernel/printk/printk_safe.c

@@ -20,7 +20,7 @@
  * is later flushed into the main ring buffer via IRQ work.
  *
  * The alternative implementation is chosen transparently
- * by examinig current printk() context mask stored in @printk_context
+ * by examining current printk() context mask stored in @printk_context
  * per-CPU variable.
  *
  * The implementation allows to flush the strings also from another CPU.