[PATCH] sysfs: fix duplicate driver registration error

o Do not release existing directory if the new directory happens to be a
  duplicate directory. Thanks to Kay Sievers for the testcase.
Signed-off-by: Maneesh Soni <maneesh@in.ibm.com>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

fs/sysfs/dir.c

@@ -111,7 +111,7 @@ static int create_dir(struct kobject * k, struct dentry * p,
 				d_rehash(*d);
 			}
 		}
-		if (error)
+		if (error && (error != -EEXIST))
 			d_drop(*d);
 		dput(*d);
 	} else