sgsnemu: Free strings in error path

In create_pdp_conf(), we have to free() any strings both in the
success and in the error case.

Change-Id: If59cc8d6d151c123f46c1d029091209fd82b3c8e
Fixes: Coverity CID#187636, CID#187633
diff --git a/sgsnemu/sgsnemu.c b/sgsnemu/sgsnemu.c
index 0b0fba6..c31f875 100644
--- a/sgsnemu/sgsnemu.c
+++ b/sgsnemu/sgsnemu.c
@@ -1459,9 +1459,9 @@
 					"router advertisements; SLAAC will not suceed, please "
 					"fix your setup!\n");
 			}
-			free(accept_ra);
-			free(forwarding);
 		}
+		free(accept_ra);
+		free(forwarding);
 	}
 
 	ipset((struct iphash_t *)pdp->peer, &addr);