ceph: don't null-terminate xattr values

For some reason, ceph_setxattr() allocates an extra byte in which a
'\0' is stored past the end of an extended attribute value.  This is
not needed, and is potentially misleading, so get rid of it.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>

fs/ceph/xattr.c

@@ -730,11 +730,9 @@ int ceph_setxattr(struct dentry *dentry, const char *name,
 		goto out;
 
 	if (val_len) {
-		newval = kmalloc(val_len + 1, GFP_NOFS);
+		newval = kmemdup(value, val_len, GFP_NOFS);
 		if (!newval)
 			goto out;
-		memcpy(newval, value, val_len);
-		newval[val_len] = '\0';
 	}
 
 	xattr = kmalloc(sizeof(struct ceph_inode_xattr), GFP_NOFS);