Use the unused /dev/hvc1 as the ramdump sink

pvmfw seems to have a hard limit on the number of PCI devices. Until
that is fixed, don't add a new PCI device, but use the existing (but
used) one.

Bug: N/A
Test: watch TH
Change-Id: I6ab7f3c2a3a072b28afa9601c617ec461fbeed93
diff --git a/virtualizationservice/src/aidl.rs b/virtualizationservice/src/aidl.rs
index af5029a..f925394 100644
--- a/virtualizationservice/src/aidl.rs
+++ b/virtualizationservice/src/aidl.rs
@@ -466,7 +466,7 @@
 
         // Creating this ramdump file unconditionally is not harmful as ramdump will be created
         // only when the VM is configured as such. `ramdump_write` is sent to crosvm and will
-        // be the backing store for the /dev/hvc3 where VM will emit ramdump to. `ramdump_read`
+        // be the backing store for the /dev/hvc1 where VM will emit ramdump to. `ramdump_read`
         // will be sent back to the client (i.e. the VM owner) for readout.
         let ramdump_path = temporary_directory.join("ramdump");
         let ramdump = prepare_ramdump_file(&ramdump_path).map_err(|e| {