[css-grid] spec nit: "swap...inline and block" disclaimer is unnecessary, in section 9.5

CSS Grid Section 9.5 has this disclaimer right before the algorithm:
  # To aid in clarity, this algorithm is written with
  # the assumption that grid-auto-flow has row specified.
  # If it is instead set to column, swap all mentions of
  # rows and columns, inline and block, etc. in this
  # algorithm.
http://dev.w3.org/csswg/css-grid/#grid-item-placement-algorithm

The mention of "inline and block" at the end there is unnecessary &
should be removed IMO. The algorithm never actually mentions the terms
"inline" or "block", so there's no need to say that they should be swapped.

~Daniel