get rid of a warning - it's ok to unwrap() here

and we unwrap() to panic on any new Err returned
from a future ncurses implementation change.

newterm https://github.com/jeaye/ncurses-rs/blob/3aa22bc279e4929e3ab69d49f75a18eda3e431e9/src/lib.rs#L1023-L1029
CString::new https://doc.rust-lang.org/std/ffi/struct.CString.html#method.new

cursive/src/backends/curses/n.rs

@@ -110,7 +110,12 @@ impl Backend {
             let path = CString::new(output_path).unwrap();
             unsafe { libc::fopen(path.as_ptr(), mode.as_ptr()) }
         };
-        ncurses::newterm(None, output, input);
+        let _ = ncurses::newterm(None, output, input).unwrap();
+        // unwrap() is guaranteed not* to panic here  ^  unless the underlaying
+        // ncurses-rs implementation changes API in the future and returns Err
+        // for other reasons as well, which we do want to catch/panic due to.
+        // *because no string is being passed as the first arg. to newterm
+
         // Enable keypad (like arrows)
         ncurses::keypad(ncurses::stdscr(), true);