cleanup: silence std::move()-related Coverity warnings

Unfortunately Coverity doesn't understand that most Qt data
structures are copy-on-write. It's a mis-feature of Qt, but
it is the way it is. Thus, passing by value is not an issue.

Out of ca. 25 warnings only two were legit. Let's silence
the others by either std::move()ing or passing by reference,
as would be idiomatic C++, which Qt is not.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

commands/command_pictures.cpp

@@ -83,7 +83,7 @@ static std::vector<PictureListForAddition> removePictures(std::vector<PictureLis
 		if (!toAdd.pics.empty())
 			res.push_back(toAdd);
 		invalidate_dive_cache(list.d);
-		emit diveListNotifier.picturesRemoved(list.d, filenames);
+		emit diveListNotifier.picturesRemoved(list.d, std::move(filenames));
 	}
 	picturesToRemove.clear();
 	return res;