9p: Remove potentially bad parameter from function entry debug print.

Signed-off-by: Duane Griffin <duaneg@dghda.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 8314d3f..7c735283 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -1022,7 +1022,8 @@
 {
 	char *s = nd_get_link(nd);
 
-	P9_DPRINTK(P9_DEBUG_VFS, " %s %s\n", dentry->d_name.name, s);
+	P9_DPRINTK(P9_DEBUG_VFS, " %s %s\n", dentry->d_name.name,
+		IS_ERR(s) ? "<error>" : s);
 	if (!IS_ERR(s))
 		__putname(s);
 }