Use correct gersion of zfs_getattr_fast() for 5.12 kernel

Update to chase that zfs_getattr_fast() will need to have the correct
version called where getattr() requires a struct user_namespace*
argument.

Signed-off-by: Coleman Kane <[email protected]>

Author: ckane

module/os/linux/zfs/zpl_inode.c

@@ -356,7 +356,11 @@ zpl_getattr_impl(const struct path *path, struct kstat *stat, u32 request_mask,
 	 * XXX request_mask and query_flags currently ignored.
 	 */
 
+#ifdef HAVE_USERNS_IOPS_GETATTR
+	error = -zfs_getattr_fast(user_ns, path->dentry->d_inode, stat);
+#else
 	error = -zfs_getattr_fast(path->dentry->d_inode, stat);
+#endif
 	spl_fstrans_unmark(cookie);
 	ASSERT3S(error, <=, 0);