Comment # 1 on bug 1215826 from Felix Miata

Something to try: Remove resume=/dev/sda2 from /etc/default/grub and
/boot/grub2/grub.cfg entirely, or replacing it with resume=UUID=<swapUUID> or
resume=LABEL=<swapLABEL> (using the actual UUID or LABEL from lsblk -f or
blkid). To test whether this is the right track, strike the E key at the Grub
menu and change resume=/dev/sda2 to noresume before proceeding with boot.
Noresume means what it spells, but it should boot straight away if I'm right.