blk_name() is not modifying data passed to it through pointer and it
returns also a pointer to const so the argument can be made const for
code safeness.
Signed-off-by: NKrzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>