NLM: Fix double free in __nlm_async_call

NLM: Fix double free in __nlm_async_call

rpc_call_async() will always call rpc_release_calldata(), so it is an
error for __nlm_async_call() to do so as well.

Addresses http://bugzilla.kernel.org/show_bug.cgi?id=7923

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Jan "Yenya" Kasprzak <kas@fi.muni.cz>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>