Cleanup some more llpvm_changes flags

I was doing another change in vm tool codebase, and the `llpvm_changes`
flag was bugging me, hence this patch :)

Bug: 365767108
Test: m
Change-Id: I8172514617f400c01c73d9a107d4db15430cbce5
diff --git a/android/vm/src/main.rs b/android/vm/src/main.rs
index ff846a1..7178de5 100644
--- a/android/vm/src/main.rs
+++ b/android/vm/src/main.rs
@@ -22,8 +22,6 @@
     CpuOptions::CpuTopology::CpuTopology, IVirtualizationService::IVirtualizationService,
     PartitionType::PartitionType, VirtualMachineAppConfig::DebugLevel::DebugLevel,
 };
-#[cfg(not(llpvm_changes))]
-use anyhow::anyhow;
 use anyhow::{bail, Context, Error};
 use binder::{ProcessState, Strong};
 use clap::{Args, Parser};
@@ -220,7 +218,6 @@
     instance: PathBuf,
 
     /// Path to file containing instance_id. Required iff llpvm feature is enabled.
-    #[cfg(llpvm_changes)]
     #[arg(long = "instance-id-file")]
     instance_id: PathBuf,
 
@@ -255,26 +252,8 @@
         }
     }
 
-    fn instance_id(&self) -> Result<PathBuf, Error> {
-        cfg_if::cfg_if! {
-            if #[cfg(llpvm_changes)] {
-                Ok(self.instance_id.clone())
-            } else {
-                Err(anyhow!("LLPVM feature is disabled, --instance_id flag not supported"))
-            }
-        }
-    }
-
-    fn set_instance_id(&mut self, instance_id_file: PathBuf) -> Result<(), Error> {
-        cfg_if::cfg_if! {
-            if #[cfg(llpvm_changes)] {
-                self.instance_id = instance_id_file;
-                Ok(())
-            } else {
-                let _ = instance_id_file;
-                Err(anyhow!("LLPVM feature is disabled, --instance_id flag not supported"))
-            }
-        }
+    fn set_instance_id(&mut self, instance_id_file: PathBuf) {
+        self.instance_id = instance_id_file;
     }
 }