Previously changed kernel versions would not cachebust the patch
download, because it would still be using the same SHA hash.
Forcing a different store path (by adding the version to the name)
also forces a redownload of the patch (and in turn cause the hash to
mismatch), avoiding this as a silent cause of failures in channel
updates.
Change-Id: I81a136ee2401126795cf042b0aadf2a1e7a707b4
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2114
Tested-by: BuildkiteCI
Reviewed-by: glittershark <grfn@gws.fyi>