rust: Fix cargo clippy and cargo doc findings

Fix the new `cargo clippy` and `cargo doc` findings that were triggered
with the recent policy addition.

Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Reviewed-by: Steffen Eiden <seiden@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>

rust/pvattest/src/cmd/verify.rs

@@ -50,7 +50,7 @@ impl<'a> VerifyOutput<'a> {
     }
 }
 
-impl<'a> Display for VerifyOutput<'a> {
+impl Display for VerifyOutput<'_> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         writeln!(f, "Config UID:")?;
         writeln!(f, "{:#}", self.cuid)?;