RPM: Remove old versions of DKMS on upgrade

Due to a mismatch between the text and a regex looking for that text,
the %preuninstall script would never run the dkms remove command
necessary to avoid corrupting the DKMS data configuration. Increase
regex specificity to avoid this issue.

Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chris Lindee <chris.lindee+github@gmail.com>
Closes: #9891
Closes #10327