Do not print out "Error encountered"

The error will print out its own description of itself as an error, so
this extra error text is redundant.

Signed-off-by: mulhern <amulhern@redhat.com>

src/bin/stratisd-tools.rs

@@ -77,7 +77,7 @@ fn main() {
         match c.run(stripped_args) {
             Ok(()) => {}
             Err(e) => {
-                eprintln!("Error encountered: {e}");
+                eprintln!("{e}");
                 process::exit(1);
             }
         }