Take the rc4 code out of ng_mppc module so we don't fail to load when

we have the rc4 code already in the kernel (via wlan stuff or awi).
Add a dependency on the rc4 module so if it doesn't exist then load it.

Reviewed by:	archie

sys/modules/netgraph/mppc/Makefile

@@ -15,8 +15,7 @@ SRCS+=	mppcc.c mppcd.c
 
 .if ${NETGRAPH_MPPC_ENCRYPTION} > 0
 .PATH: ${.CURDIR}/../../../crypto
-.PATH: ${.CURDIR}/../../../crypto/rc4
-SRCS+=	rc4.c sha1.c
+SRCS+= sha1.c
 .endif
 
 opt_netgraph.h:

sys/netgraph/ng_mppc.c

@@ -170,6 +170,11 @@ static struct ng_type ng_mppc_typestruct = {
 };
 NETGRAPH_INIT(mppc, &ng_mppc_typestruct);
 
+#ifdef NETGRAPH_MPPC_ENCRYPTION
+/* Depend on separate rc4 module */
+MODULE_DEPEND(ng_mppc, rc4, 1, 1, 1);
+#endif
+
 /* Fixed bit pattern to weaken keysize down to 40 or 56 bits */
 static const u_char ng_mppe_weakenkey[3] = { 0xd1, 0x26, 0x9e };