driver core: fix comments for device_block_probing()

Correct function name and spelling/typo for device_block_probing()
in drivers/base/dd.c.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>