[IPCONFIG]: Mark vendor_class_identifier as __initdata.

Based upon a suggestion by Francois Romieu.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/ipconfig.c

@@ -140,7 +140,8 @@ __be32 ic_servaddr = NONE;	/* Boot server IP address */
 __be32 root_server_addr = NONE;	/* Address of NFS server */
 u8 root_server_path[256] = { 0, };	/* Path to mount as root */
 
-static char vendor_class_identifier[253]; /* vendor class identifier */
+/* vendor class identifier */
+static char vendor_class_identifier[253] __initdata;
 
 /* Persistent data: */