efi_loader: RestoreTPL should execute queued events

When the TPL is lowered queued events may become eligible for execution.

iPXE uses the following pattern to request event execution:

	bs->RestoreTPL ( TPL_APPLICATION );
	bs->RaiseTPL ( TPL_CALLBACK );

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>

lib/efi_loader/efi_boottime.c

@@ -278,6 +278,11 @@ static void EFIAPI efi_restore_tpl(efi_uintn_t old_tpl)
 	if (efi_tpl > TPL_HIGH_LEVEL)
 		efi_tpl = TPL_HIGH_LEVEL;
 
+	/*
+	 * Lowering the TPL may have made queued events eligible for execution.
+	 */
+	efi_timer_check();
+
 	EFI_EXIT(EFI_SUCCESS);
 }