Optimize away an owned string in path_readlink.

src/host.rs

@@ -508,14 +508,6 @@ pub(crate) fn path_from_slice<'a>(s: &'a [u8]) -> Result<&'a str> {
     str::from_utf8(s).map_err(|_| Error::EILSEQ)
 }
 
-/// Creates owned WASI path from byte vector.
-///
-/// NB WASI spec requires bytes to be valid UTF-8. Otherwise,
-/// `__WASI_EILSEQ` error is returned.
-pub(crate) fn path_from_vec<S: Into<Vec<u8>>>(s: S) -> Result<String> {
-    String::from_utf8(s.into()).map_err(|_| Error::EILSEQ)
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

src/hostcalls_impl/fs.rs

@@ -652,7 +652,7 @@ pub(crate) unsafe fn path_readlink(
     enc_usize_byref(memory, buf_used, 0)?;
 
     let dirfd = dec_fd(dirfd);
-    let path = dec_slice_of::<u8>(memory, path_ptr, path_len).and_then(host::path_from_vec)?;
+    let path = dec_slice_of::<u8>(memory, path_ptr, path_len).and_then(host::path_from_slice)?;
 
     trace!("     | (path_ptr,path_len)='{}'", &path);