Fix ifa refcount leak during route addition.

[melifaro]

Summary

Routing code relies on stable ifa's during route creation.
This is needed due to the fact that nhop objects stores (referenced) ifa object for the whole nhop object lifetime.

To avoid the situation when ifa gets scheduled for the deleted during the route addition process, rt_getifa_fib() references found ifa as soon as possible.

Plug refcount leak by freeing ifa reference immediately after creating nexthop, regardless of the result.

[mjg]

is this waiting on anything?

[melifaro]

Landed as a375ec52a7b423133f66878ecf002efc3b6e9fca .

sys/net/route/route_ctl.c

 /* $FreeBSD$ */
 OUTPUT_FORMAT("elf64-x86-64-freebsd", "elf64-x86-64-freebsd", "elf64-x86-64-freebsd")
 OUTPUT_ARCH(i386:x86-64)
 ENTRY(btext)
 SEARCH_DIR("/usr/lib");
 SECTIONS
 {
+  kernphys = kernload;
   /* Read-only sections, merged into text segment: */
-  kernphys = 0x200000; /* 2MB superpage size */
   . = kernbase + kernphys + SIZEOF_HEADERS;
   /*
    * Use the AT keyword in order to set the right LMA that contains
    * the physical address where the section should be loaded. This is
    * needed for the Xen loader which honours the LMA.
    */
   .interp         : AT (kernphys + SIZEOF_HEADERS) { *(.interp) }
   .hash           : { *(.hash) }