eeprom: at24: arrange local variables

Arrange declarations of local variables by line length as visually
it's easier to read.

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Tested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>