slirp: Replace m_freem with m_free

Remove this pointless wrapping.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/slirp/udp.c b/slirp/udp.c
index cefd50b..5b060f3 100644
--- a/slirp/udp.c
+++ b/slirp/udp.c
@@ -222,7 +222,7 @@
 
 	return;
 bad:
-	m_freem(m);
+	m_free(m);
 	return;
 }