[libmultipath] move snprint_[path|map]() to format based printing fns

[libmultipath] move snprint_[path|map]() to format based printing fns

 * path format magics :
 *
 * %w : multipath uid
 * %i : scsi tuple
 * %d : device name
 * %D : device major:minor
 * %t : device mapper path status
 * %T : checker path status
 * %s : scsi strings
 * %c : claimed
 *
 * map format magics :
 *
 * %w : multipath uid
 * %d : DM device name
 * %F : failback countdown
 * %C : checker countdown

and update all callers (nice cleanup).

The printing buffer overflow checking is done right at last.