twrp.cpp: adjust fastbootd prop set for module loading

ro.boot.fastboot is already used for when an image
is booted via fastboot boot. In order to avoid conflicts
and double triggering, adjust prop name to
"ro.twrp.fastbootd"

Change-Id: If55436dd836d275b25887cf4c7c5a6f762f496e1
diff --git a/twrp.cpp b/twrp.cpp
index 9c6882b..02f88e9 100644
--- a/twrp.cpp
+++ b/twrp.cpp
@@ -395,7 +395,7 @@
 #ifdef TW_LOAD_VENDOR_MODULES
 	if (startup.Get_Fastboot_Mode()) {
 		TWPartition* ven_dlkm = PartitionManager.Find_Partition_By_Path("/vendor_dlkm");
-		android::base::SetProperty("ro.boot.fastboot", "1");
+		android::base::SetProperty("ro.twrp.fastbootd", "1");
 		PartitionManager.Prepare_Super_Volume(PartitionManager.Find_Partition_By_Path("/vendor"));
 		if(ven_dlkm) {
 			PartitionManager.Prepare_Super_Volume(ven_dlkm);