Fixed a couple of comments on TimeSpan.SecondsPerTick and Thread.SleepInternal (#18276)
Fixed a couple of comments on TimeSpan.SecondsPerTick and Thread.SleepInternal (#18276)

* Fixed comment for TimeSpan.SecondsPerTick

* Fixed comment on Thread.SleepInternal

Signed-off-by: dotnet-bot-corefx-mirror <03c4cb6107ae99956a7681f2c97ff7104809a2bd@microsoft.com>

ptoonen/corefx,ericstj/corefx,shimingsg/corefx,wtgodbe/corefx,BrennanConroy/corefx,ericstj/corefx,mmitche/corefx,shimingsg/corefx,ptoonen/corefx,Jiayili1/corefx,ericstj/corefx,ViktorHofer/corefx,shimingsg/corefx,ptoonen/corefx,Jiayili1/corefx,ptoonen/corefx,ptoonen/corefx,ViktorHofer/corefx,Jiayili1/corefx,ViktorHofer/corefx,Jiayili1/corefx,ViktorHofer/corefx,ViktorHofer/corefx,ericstj/corefx,Jiayili1/corefx,wtgodbe/corefx,shimingsg/corefx,wtgodbe/corefx,Jiayili1/corefx,Jiayili1/corefx,ptoonen/corefx,shimingsg/corefx,ericstj/corefx,mmitche/corefx,ericstj/corefx,mmitche/corefx,mmitche/corefx,wtgodbe/corefx,ericstj/corefx,ptoonen/corefx,mmitche/corefx,BrennanConroy/corefx,BrennanConroy/corefx,shimingsg/corefx,wtgodbe/corefx,mmitche/corefx,ViktorHofer/corefx,wtgodbe/corefx,mmitche/corefx,ViktorHofer/corefx,wtgodbe/corefx,shimingsg/corefx