Function blkid_parse_line

* Parse a single line of data, and return a newly allocated dev struct. * Add the new device to the cache struct, if one was read. * * Lines are of the form /dev/foo * * Returns -ve value on error. * Returns 0 otherwise. * If a valid device was read, *dev_p is non-NULL, otherwise it is NULL * (e.g. comment lines, unknown XML content, etc). */