Description of problem:
  Command `grub2-mkconfig -o /boot/grub2/grub.cfg` failed with message "/etc/tuned/bootcmdline: line 27: $'\n': command not found"

Version-Release number of selected component (if applicable):
  tuned-2.5.1-4.el7_2.6.noarch

How reproducible:
  always

Steps to Reproduce:
1. Have machine with at least 8 cpu
2. Do these steps:
   # mkdir /etc/tuned/custom
   # echo "[bootloader]
   cmdline=isolcpus=\${f:cpulist_invert:1-3,6}" > /etc/tuned/custom/tuned.conf
   # tuned-adm profile custom
   # grub2-mkconfig -o /boot/grub2/grub.cfg
  
Actual results:
   # grub2-mkconfig -o /boot/grub2/grub.cfg
   Generating grub configuration file ...
   /etc/tuned/bootcmdline: line 27: $'\n': command not found
   # echo $?
   127

Expected results:
   End without error

Information for QA:
   Failed test case:
   /CoreOS/tuned/Sanity/built-in-support-for-unit-conversion