Current calculate timeout logic may have overflow if the input timeout value too large. This patch fix this potential overflow issue. V2: Use local variable instead of call GetPerformanceCounterProperties twice. Also correct some comments. Cc: Michael Kinney <michael.d.kinney@intel.com> Cc: Ruiyu Ni <ruiyu.ni@intel.com> Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Eric Dong <eric.dong@intel.com> Reviewed-by: Michael Kinney <michael.d.kinney@intel.com>