net/slirp.c: Fix spelling error in error message

DNS should be DHCP

Signed-off-by: Doug Evans <dje@google.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Message-Id: <20210122004251.843837-1-dje@google.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

net/slirp.c

@@ -473,7 +473,7 @@ static int net_slirp_init(NetClientState *peer, const char *model,
         return -1;
     }
     if (dhcp.s_addr == host.s_addr || dhcp.s_addr == dns.s_addr) {
-        error_setg(errp, "DNS must be different from host and DNS");
+        error_setg(errp, "DHCP must be different from host and DNS");
         return -1;
     }