Fix the commit difference computation in roll_deps
Fix the commit difference computation in roll_deps

(can't use commit hashes...)

TBR=phoglund@webrtc.org

Bug: webrtc:8688
No-Try: True
Change-Id: I60d7f72c1fcf2b9cfae4ba780cb3fa97ff347127
Reviewed-on: https://webrtc-review.googlesource.com/36442
Commit-Queue: Oleh Prypin <5baa3e04f9bd6ba7a2a4b56625a3c84f19237cdb@webrtc.org>
Reviewed-by: Oleh Prypin <5baa3e04f9bd6ba7a2a4b56625a3c84f19237cdb@webrtc.org>
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#21455}
ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc