More info about swap files: here

Step 1: turn off quiet boot to observe the process

# Edit the grub file
sudo nano /etc/default/grub
# Comment out this line or replace the value to “profile”
GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash”
# Save the file and reboot
sudo reboot

Step 2: Find the UUID of the swap file

# Locate swap file
grep -w swap /etc/fstab
# Get UUID
swapfilepath=/dev/zvol/rpool/swap # this path would be different on your system
sudo swaplabel $swapfilepath
# Sample output
UUID: 1c132109-c38c-449d-9507-a07b7f54c7f6

Step 3: 

# Edit the resume file
sudo vim /etc/initramfs-tools/conf.d/resume
# update it with the correct UUID
RESUME=UUID=1c132109-c38c-449d-9507-a07b7f54c7f6
# can also set RESUME=NONE to bypass the swap file
# save and reboot system
sudo update-initramfs -u
sudo reboot