This patch fixes a problem introduced by commit
61bb6eeb4d.
The PcdSnpCreateExitBootServicesEvent is not guaranteed to be FixedAtBuild,
so use PcdGetBool() to supports both fixed and patchable PCD.
Cc: Jiaxin Wu <jiaxin.wu@intel.com>
Signed-off-by: Siyuan Fu <siyuan.fu@intel.com>
Reviewed-by: Jiaxin Wu <jiaxin.wu@intel.com>
6f3ac73cd3