refactor: fix warnings

libsys/src/calls.rs

@@ -472,5 +472,5 @@ pub fn sys_mmap(
 
 #[inline(always)]
 pub unsafe fn sys_munmap(addr: usize, len: usize) -> Result<(), Errno> {
-    Errno::from_syscall_unit(unsafe { syscall!(SystemCall::UnmapMemory, argn!(addr), argn!(len)) })
+    Errno::from_syscall_unit(syscall!(SystemCall::UnmapMemory, argn!(addr), argn!(len)))
 }

libsys/src/stat.rs

@@ -274,8 +274,7 @@ impl fmt::Display for FileMode {
             choose(self.contains(Self::OTHER_READ), 'r', '-'),
             choose(self.contains(Self::OTHER_WRITE), 'w', '-'),
             choose(self.contains(Self::OTHER_EXEC), 'x', '-'),
-        );
-        Ok(())
+        )
     }
 }