executor: fix get var expr when session var is hex literal (#23241)#23372

Merged

ti-chi-bot merged 1 commit intopingcap:release-4.0from ti-srebot:release-4.0-2890a8f62c32

Mar 18, 2021

+112-7

Commits on Mar 17, 2021

cherry pick pingcap#23241 to release-4.0

guo-shaoge
authored and
ti-srebot
committed