Description of problem:

Upon installation, storaged's rpm scriptlets issue this error message:
/var/tmp/rpm-tmp.jtjzOB: line 1: udevadm: command not found
/var/tmp/rpm-tmp.jtjzOB: line 2: udevadm: command not found


Version-Release number of selected component (if applicable):
storaged-2.6.3-4.fc26.x86_64

How reproducible:
Always.

Steps to Reproduce:
1. mock -r fedora-26-x86_64 --install storaged

Actual results:
..
  Installing  : storaged-2.6.3-4.fc26.x86_64                                                                                                                       47/47 
/var/tmp/rpm-tmp.jtjzOB: line 1: udevadm: command not found
/var/tmp/rpm-tmp.jtjzOB: line 2: udevadm: command not found


Additional info:
- This looks like a missing package dependency to me.
- The same issue exists in rawhide:
  mock -r fedora-26-x86_64 --install udisks2