Description of problem:

Trying to build an initrd for a monolithic kernel fails because mkinitrd expects
a module tree for a the kernel in /lib/modules and a modules.dep file in there.

Version-Release number of selected component (if applicable):

mkinitrd-5.0.32-1

How reproducible:

Steps to Reproduce:
1. Build a custom kernel without module support
2. Try to make an initrd for it using mkinitrd
3.
  
Actual results:

mkinitrd stops with message:
No modules available for kernel "xyz"

Expected results:

An initrd matching the monolithic kernel should be built. There should be a
command line switch to mkinitrd that causes the module tree check to be skipped.

Additional info:

An initrd for a monolithic kernels is required when using a software RAID or LVM
device for the root filesystem. A workaround to the issue is creating the
expected directory under /lib/modules, and in there an empty modules.dep file.