super: set a prop after symlinks are created

This allows actions to be triggered once the super partitions
are available.

This is helpful when adjustments need to be made to the
device ramdisk based on the installed system.

Change-Id: I980d8ed481356dc75ce2fa99ae8d60e7c704eb86
diff --git a/partitionmanager.cpp b/partitionmanager.cpp
index fe71652..47a9db5 100755
--- a/partitionmanager.cpp
+++ b/partitionmanager.cpp
@@ -3431,6 +3431,7 @@
 	if (access(("/dev/block/bootdevice/by-name/" + bare_partition_name).c_str(), F_OK) == -1) {
 		LOGINFO("Symlinking %s => /dev/block/bootdevice/by-name/%s \n", fstabEntry.blk_device.c_str(), bare_partition_name.c_str());
 		symlink(fstabEntry.blk_device.c_str(), ("/dev/block/bootdevice/by-name/" + bare_partition_name).c_str());
+		property_set("twrp.super.symlinks_created", "true");
 	}
 
     return true;