Reinstall (bless) rEFInd after Mac OS X update

If you are using Mac OS X 10.11 or later boot into recovery mode (command+R while booting) and in the terminal disable SIP:

$ csrutil disable

Restart and then check in what partition is EFI installed:

$ diskutil list | grep EFI
   1:   EFI EFI      209.7 MB   disk0s1

Then:

$ sudo mkdir /Volumes/EFI
$ sudo mount -t msdos /dev/disk0s1 /Volumes/EFI
$ sudo bless --mount /Volumes/EFI --setBoot --file /Volumes/EFI/EFI/refind/refind_x64.efi --shortform
$ sudo diskutil unmount /Volumes/EFI

Enable SIP again in the recovery mode if needed:

$ csrutil enable