How to reinstall the latest kernel and rebuild initramfs.

Find the latest kernel.

rpm -qa kernel
kernel-3.10.0-1160.6.1.el7.x86_64
kernel-3.10.0-1160.11.1.el7.x86_64

Remove the kernel first, then reinstall.

yum remove kernel-3.10.0-1160.6.1.el7.x86_64
yum install kernel-3.10.0-1160.6.1.el7.x86_64