+++ This bug was initially created as a clone of Bug #1139783 +++

I decided to keep the original one to track the AutoYaST issue (which ignores
an LV been used as part of a bcache setup) and create this clone to track the
problems with bcache triggered by using the Expert Partitioner.

Using such tool, the user can use LVM LV for bcache. It accepts nicely until it
actually do partitioning.

It tries to run:

 # /usr/sbin/bcache set-cachemode /dev/system-slow/home-back writethrough
 Error:Wrong device name found

While this one works:

 # /usr/sbin/bcache set-cachemode $(readlink -f /dev/system-slow/home-back)
writethrough

It accepts /dev/dm-* but not /dev/system-slow/home-back.

The same goes with "bcache attach" that does not follow symlinks.

After installation finish, it works as expected. The only caveat (probably
related) is that systemd waits until it times out for a resume= device (kernel
cmdline resume=/dev/disk/by-id/ata-VBOX_HARDDISK_VB4e22b7b1-3df6870d-part3)
while my disks have 2 partitions or less and swap is a LVM LV at
/dev/system/swap. Fixing that at /etc/default/grub and updating grub.cfg fixes
the problem.

In summary (for this particular bug report):

1) Since the bcache tools seem to not follow symlinks, libstorage-ng should
follow call them with the proper file name (or with any flag that makes the
tools follow the symlinks).
2) yast2-bootloader should not write the wrong (non-existing) device into
/etc/default/grub:GRUB_CMDLINE_LINUX_DEFAULT