[Leapp] IPU is inhibited due to mptctl module that cannot be unloaded

Issue

Leapp reports the following inhibitor:

Risk Factor: high (inhibitor)
Title: Leapp detected loaded kernel drivers which have been removed in RHEL 8. Upgrade cannot proceed.
Summary: Support for the following RHEL 7 device drivers has been removed in RHEL 8:
     - mptctl

lspci does not show any storage hardware behind this module. But the module cannot be downloaded anyway:

# rmmod mptctl
rmmod: ERROR: Module mptctl is in use