common/reflink: fix error messages in _require_scratch_dedupe()

In case dedupe returns an error in _require_scratch_dedupe(),
report the error for the scratch rather than for the test
filesystem.

Signed-off-by: Anthony Iliopoulos <ailiopoulos@suse.com>
Reviewed-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>
1 file changed