slirp: Drop link_up checks from if_output and slirp_socket_can_recv

link_up is true once slirp is initialized, so these check are really not
required.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

slirp/if.c

diff --git a/slirp/if.c b/slirp/if.c
index 1ef4bf9..58ab4c7 100644
--- a/slirp/if.c
+++ b/slirp/if.c
@@ -138,10 +138,7 @@
 	/*
 	 * This prevents us from malloc()ing too many mbufs
 	 */
-	if (link_up) {
-		/* if_start will check towrite */
-		if_start();
-	}
+	if_start();
 #endif
 }
 

slirp/slirp.c

diff --git a/slirp/slirp.c b/slirp/slirp.c
index 9b51c0b..71f79a3 100644
--- a/slirp/slirp.c
+++ b/slirp/slirp.c
@@ -824,9 +824,6 @@
 	struct iovec iov[2];
 	struct socket *so;
 
-    if (!link_up)
-        return 0;
-
 	so = slirp_find_ctl_socket(guest_addr, guest_port);
 
 	if (!so || so->so_state & SS_NOFDREF)