pstore: Improve and update some comments and status output

This improves and updates some comments:
 - dump handler comment out of sync from calling convention
 - fix kern-doc typo

and improves status output:
 - reminder that only kernel crash dumps are compressed
 - do not be silent about ECC infrastructure failures

Signed-off-by: Kees Cook <keescook@chromium.org>

include/linux/pstore.h

@@ -85,7 +85,7 @@ struct pstore_record {
 /**
  * struct pstore_info - backend pstore driver structure
  *
- * @owner:	module which is repsonsible for this backend driver
+ * @owner:	module which is responsible for this backend driver
  * @name:	name of the backend driver
  *
  * @buf_lock:	spinlock to serialize access to @buf