split out elfloader and adjust mutability

xencall/examples/domain_create.rs

@@ -3,8 +3,8 @@ use xencall::sys::CreateDomain;
 use xencall::{XenCall, XenCallError};
 
 fn main() -> Result<(), XenCallError> {
-    let mut call = XenCall::open()?;
-    let mut domctl: DomainControl = DomainControl::new(&mut call);
+    let call = XenCall::open()?;
+    let domctl: DomainControl = DomainControl::new(&call);
     let info = domctl.create_domain(CreateDomain::default())?;
     println!("created domain {}", info.domid);
     Ok(())

xencall/examples/domain_info.rs

@@ -2,8 +2,8 @@ use xencall::domctl::DomainControl;
 use xencall::{XenCall, XenCallError};
 
 fn main() -> Result<(), XenCallError> {
-    let mut call = XenCall::open()?;
-    let mut domctl: DomainControl = DomainControl::new(&mut call);
+    let call = XenCall::open()?;
+    let domctl: DomainControl = DomainControl::new(&call);
     let info = domctl.get_domain_info(1)?;
     println!("{:?}", info);
     Ok(())

xencall/examples/version_capabilities.rs

@@ -1,7 +1,7 @@
 use xencall::{XenCall, XenCallError};
 
 fn main() -> Result<(), XenCallError> {
-    let mut call = XenCall::open()?;
+    let call = XenCall::open()?;
     let info = call.get_version_capabilities()?;
     println!("{:?}", info);
     Ok(())