Shorten tau trigger SF decoration name
Follow up to !71743 (merged)
The current decoration for the tau trigger SF includes the HLT
prefix in the name as tau_trigEffSF_HLT_tau35_medium1_tracktwo
. For consistency with !71812 (merged) and !71968 (merged), with electrons and muons, shorten this into tau_trigEffSF_tau35_medium1_tracktwo
.