The debug wrappers for CloseEvent() and CheckEvent() are currently
both calling SignalEvent() instead (presumably due to copy-paste
errors). Astonishingly, this has generally not prevented a successful
boot in the (very rare) case that DEBUG=efi_wrap is enabled.
Fix the wrappers to call the intended functions.
Signed-off-by: Michael Brown <mcb30@ipxe.org>