There were no "fence-sitting" Senators for this vote - all voting Republicans wanted to remove privacy protections. All Democratic and Independent Senators voted to keep privacy protections in place.
The Senate is 52R, 46D, 2I, there were 2 abstentions during the Vote so there was some fence sitting at least on the R side, and they've decided to chick out completely.
The two non-voting senators were Republicans. One was Rand Paul who co-sponsored the bill, apparently there's some tradition of not voting for your own bill (when there are votes to spare). The other one, Isakson, is recovering from surgery and not in D.C. to vote.