uapi: nfnetlink_cthelper.h: fix userspace compilation error

Apparently, <linux/netfilter/nfnetlink_cthelper.h> and
<linux/netfilter/nfnetlink_acct.h> could not be included into the same
compilation unit because of a cut-and-paste typo in the former header.

Fixes: 12f7a505331e6 ("netfilter: add user-space connection tracking helper infrastructure")
Cc: <[e-mail]> # v3.6
Signed-off-by: Dmitry V. Levin <[e-mail]>
Signed-off-by: Pablo Neira Ayuso <[e-mail]>

include/uapi/linux/netfilter/nfnetlink_cthelper.h

···
 #define NFCT_HELPER_STATUS_DISABLED	0
 #define NFCT_HELPER_STATUS_ENABLED	1
 
-enum nfnl_acct_msg_types {
+enum nfnl_cthelper_msg_types {
 	NFNL_MSG_CTHELPER_NEW,
 	NFNL_MSG_CTHELPER_GET,
 	NFNL_MSG_CTHELPER_DEL,