net: ipconfig: move ic_nameservers_fallback into #ifdef block

The new variable is only used when IPCONFIG_BOOTP is defined and otherwise
causes a warning:

net/ipv4/ipconfig.c:177:12: error: 'ic_nameservers_fallback' defined but not used [-Werror=unused-variable]

Move it next to the user.

Fixes: 81ac2722 ("net: ipconfig: Allow DNS to be overwritten by DHCPACK")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/ipconfig.c

@@ -173,9 +173,6 @@ static int ic_proto_have_if __initdata;
 /* MTU for boot device */
 static int ic_dev_mtu __initdata;
 
-/* DHCPACK can overwrite DNS if fallback was set upon first BOOTP reply */
-static int ic_nameservers_fallback __initdata;
-
 #ifdef IPCONFIG_DYNAMIC
 static DEFINE_SPINLOCK(ic_recv_lock);
 static volatile int ic_got_reply __initdata;    /* Proto(s) that replied */
@@ -668,6 +665,9 @@ static struct packet_type bootp_packet_type __initdata = {
 	.func =	ic_bootp_recv,
 };
 
+/* DHCPACK can overwrite DNS if fallback was set upon first BOOTP reply */
+static int ic_nameservers_fallback __initdata;
+
 /*
  *  Initialize DHCP/BOOTP extension fields in the request.
  */