Comment 1 for bug 1718687

Here is the fix of the problem:

Use the right type for `len`, avoid segmentation fault

`getline()` requires its second parameter to be `size_t *`. On the amd64
platform the size of `unsigned int` is 4 and the size of `size_t` is 8
bytes. Using a wrong pointer type can lead to a stack variables
corruption (overwriting with zeros) and a segmentation fault later.

See also similar `len` declarations in `_discover_get_pci_raw_sys()` in
the docs and `_discover_get_ata_raw()` / `discover_get_pci_raw_proc()` /
`discover_get_usb_raw()` in the source code.