hm, Lets bypass this by installing a new kernel, say Linux 57
Proceed with pacman -S linux57 && mkinitcpio -P && pacman -R linux54 && mkinitcpio -P && pacman -S linux54 && mkinitcpio -P && pacman -R linux57 && mkinitcpio -P
That command will install the linux kernel 57, create a ram image of linux 57, remove linux 54, resets the images, then reinstall linux 54, create a proper ram image, remove linux 57, and only keep linux 54.
Some steps might seems unnecessary, but it is better to attack from every angles than sinking slowly! 