arch/sim/src/sim/posix/sim_hostfs.c: use host_errno_to_nx

tested with ELOOP, which is 62 on macOS and 40 on NuttX, on sim/macOS.

```shell
spacetanuki% ln -s a a
spacetanuki% cat a
cat: a: Too many levels of symbolic links
spacetanuki% ./nuttx

NuttShell (NSH) NuttX-10.4.0
nsh> mount -t hostfs -o fs=. /mnt
nsh> cat /mnt/a
nsh: cat: open failed: 40
nsh>
```

this is a follow-up of #15552
this fixes a non-linux regression in #15535

Signed-off-by: YAMAMOTO Takashi <[email protected]>

Author: yamt

arch/sim/src/sim/posix/sim_hostfs.c

@@ -37,6 +37,7 @@
 #include <errno.h>
 
 #include "hostfs.h"
+#include "sim_hosterrno.h"
 
 /****************************************************************************
  * Private Functions
@@ -46,13 +47,9 @@
  * Name: host_errno_convert
  ****************************************************************************/
 
-static int host_errno_convert(int errcode)
+static int host_errno_convert(int negative_host_errno)
 {
-  /* Provide a common interface, which should have different conversions
-   * on different platforms.
-   */
-
-  return errcode;
+  return -host_errno_to_nx(-negative_host_errno, EIO);
 }
 
 /****************************************************************************