hw/9pfs: Use the correct file descriptor in Fsdriver Callback

Fsdriver callback that operate on file descriptor need to
differentiate between directory fd and file fd.

Based on the original patch from Sassan Panahinejad <sassan@sassan.me.uk>

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
diff --git a/fsdev/file-op-9p.h b/fsdev/file-op-9p.h
index 1928da2..a85ecd3 100644
--- a/fsdev/file-op-9p.h
+++ b/fsdev/file-op-9p.h
@@ -112,10 +112,10 @@
     ssize_t (*pwritev)(FsContext *, V9fsFidOpenState *,
                        const struct iovec *, int, off_t);
     int (*mkdir)(FsContext *, V9fsPath *, const char *, FsCred *);
-    int (*fstat)(FsContext *, V9fsFidOpenState *, struct stat *);
+    int (*fstat)(FsContext *, int, V9fsFidOpenState *, struct stat *);
     int (*rename)(FsContext *, const char *, const char *);
     int (*truncate)(FsContext *, V9fsPath *, off_t);
-    int (*fsync)(FsContext *, V9fsFidOpenState *, int);
+    int (*fsync)(FsContext *, int, V9fsFidOpenState *, int);
     int (*statfs)(FsContext *s, V9fsPath *path, struct statfs *stbuf);
     ssize_t (*lgetxattr)(FsContext *, V9fsPath *,
                          const char *, void *, size_t);