ethdev: avoid documentation in next lines

ethdev: avoid documentation in next lines

Documentation in the next separate line is confusing. If documentation
requires own line it should be before, not after.

Move documentation to the previous line if documentation on the same
line makes it too long.

Fix a number of incorrect markups on the way.

When a lines is touched by the patch anyway, do other cosmetics
changes to avoid changes in next patches.

Signed-off-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
Acked-by: Ori Kam <orika@nvidia.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>