bootstrap: adapt to upstream redox-rt API changes

- ExtraInfo now requires filetable_fd and same_process fields
- fexec_impl now returns Option<FexecResult>

bootstrap/src/exec.rs

@@ -220,6 +220,8 @@ pub fn main() -> ! {
         proc_fd: init_proc_fd.as_raw_fd(),
         ns_fd: Some(initns_fd.take()),
         cwd_fd: Some(cwd_fd.as_raw_fd()),
+        filetable_fd: None,
+        same_process: false,
     };
 
     let path = "/scheme/initfs/bin/init";
@@ -233,10 +235,10 @@ pub fn main() -> ! {
 
     let exe_path = alloc::format!("/scheme/initfs{}", path);
 
-    let FexecResult::Interp {
+    let Some(FexecResult::Interp {
         path: interp_path,
         interp_override,
-    } = fexec_impl(
+    }) = fexec_impl(
         image_file,
         init_thr_fd,
         init_proc_fd,