This patch fixes copy_namespaces()'s error path.

when new nsproxy (new_ns) is created pointers to namespaces (ipc, uts) are
copied from the old nsproxy.  Later in copy_utsname, copy_ipcs, etc.
according namespaces are get-ed.  On error path needed namespaces are
put-ed, so there's no need to put new nsproxy itelf as it woud cause
putting namespaces for the second time.

Found when incorporating namespaces into OpenVZ kernel.
Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>