bindings: cxx: don't check the chip's label and name for empty strings
bindings: cxx: don't check the chip's label and name for empty strings

The core library guarantees that a GPIO chip will have a name and
a label. No need to check if the returned strings are empty.

Signed-off-by: Bartosz Golaszewski <108de5fbc428215dc26df4468b48691526611148@gmail.com>

brgl/libgpiod,brgl/libgpiod,brgl/libgpiod,brgl/libgpiod