When stboot runs as init, load modules before mounting fs
This is needed to be able to mount /sys/firmware/efi/efivars when the efivarfs driver isn't linked statically into the kernel.
Logged error message:
u-root init: error creating mount -t "efivarfs" -o "efivarfs" "/sys/firmware/efi/efivars" flags 0x0: no such device
With this fix, this error no longer occurs for the qemu-boot-from-net.sh and qemu-iso-boot-from-net.sh integration tests, while it can still be observed for qemu-boot-from-disk.sh, which doesn't provide any kernel modules.