The recent patch "UefiCpuPkg/MpInitLib: Program AP stack in fixed address"
inadvertently broke the first startup of APs during X64 PEI, because in
the TestLock section of the code, it replaced the access to the
NumApsExecuting counter with an access to the unrelated InitFlag field.
Cc: Jeff Fan <jeff.fan@intel.com>
Fixes: 845c5be1fd
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>