[linux] storage: check if devnode is valid pointer

[illiliti]

Description

Prevent segfault if udev_device_get_devnode() returned NULL.

Motivation and context

This change fixes segfault when udev_device doesn't have devnode.

How has this been tested?

Tested on Alpine linux with libudev-zero(master branch)

Types of change

• Bug fix (non-breaking change which fixes an issue)
• Clean up (non-breaking change which removes non-working, unmaintained functionality)
• Improvement (non-breaking change which improves existing functionality)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that will cause existing functionality to change)
• Cosmetic change (non-breaking change that doesn't touch code)
• None of the above (please explain below)

Checklist:

• My code follows the Code Guidelines of this project
• My change requires a change to the documentation, either Doxygen or wiki
• I have updated the documentation accordingly
• I have read the Contributing document
• I have added tests to cover my change
• All new and existing tests passed

[lrusak]

Thanks for the PR.

Can you change this to check for nullptr before even calling get_mountpoint

const char* devnode = udev_device_get_devnode(device);
if (!devnode)
{
  udev_device_unref(device);
  continue;
}

const char *mountpoint = get_mountpoint(devnode);

[illiliti]

@lrusak Done. I don't know what this bot wants from me. I already applied this diff

[fuzzard]

@lrusak you happy for this to merge?

[lrusak]

Yea looks ok.

[fuzzard]

Thanks for the contribution, apologies it lingered for so long.

[garbear]

Indeed, @illiliti congrats on your first PR merged in Kodi!