tpm: remove mixture of str and Path

`impl AsRef<Path>` is the most idiomatic way to consume paths
in Rust. I removed the mixture.

Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com

tpm/src/emulator.rs

@@ -86,10 +86,12 @@ impl Emulator {
     ///
     /// * `path` - A path to the Unix Domain Socket swtpm is listening on
     ///
-    pub fn new(path: &str) -> Result<Self> {
-        if !Path::new(&path).exists() {
+    pub fn new(path: impl AsRef<Path>) -> Result<Self> {
+        let path = path.as_ref();
+        if !path.exists() {
             return Err(Error::InitializeEmulator(anyhow!(
-                "The input TPM Socket path: {path:?} does not exist"
+                "The input TPM Socket path: {:?} does not exist",
+                path.to_str().unwrap()
             )));
         }
         let mut socket = SocketDev::new();