coprocessor/codec/mysql/duration: Fix micro_secs of Duration (#3625)
coprocessor/codec/mysql/duration: Fix micro_secs of Duration (#3625)

Signed-off-by: koushiro <716ebe8ea9ac10a44e38dbf267b3a4399137bef1@gmail.com>
BusyJay/tikv,c4pt0r/tikv,BusyJay/tikv,pingcap/tikv,BusyJay/tikv,pingcap/tikv,BusyJay/tikv