Have rootshell print errors and exit 1 if exec fails

Previously was ignoring the possible error retuned by exec, this commit
has rootshell print the error if exec returns and have the process exit
with a code of 1 instead of 0.

rootshell/src/main.rs

@@ -25,9 +25,12 @@ fn main() {
 
    // discard argv[0]
    let _ = args.next();
-   Command::new("/bin/bash")
+   // This call will only return if there is an error
+   let error = Command::new("/bin/bash")
 	.args(args)
 	.uid(0)
 	.gid(0)
 	.exec();
+   eprintln!("Error running command: {error}");
+   std::process::exit(1);
 }