build: work around broken kernel header
build: work around broken kernel header

I got this scary warning during ./configure on rawhide:

checking linux/if_bridge.h usability... no
checking linux/if_bridge.h presence... yes
configure: WARNING: linux/if_bridge.h: present but cannot be compiled
configure: WARNING: linux/if_bridge.h:     check for missing prerequisite headers?
configure: WARNING: linux/if_bridge.h: see the Autoconf documentation
configure: WARNING: linux/if_bridge.h:     section "Present But Cannot Be Compiled"
configure: WARNING: linux/if_bridge.h: proceeding with the compiler's result
configure: WARNING:     ## ------------------------------------- ##
configure: WARNING:     ## Report this to libvir-list@redhat.com ##
configure: WARNING:     ## ------------------------------------- ##
checking for linux/if_bridge.h... no

* configure.ac (AC_CHECK_HEADERS): Provide struct in6_addr, since
linux/if_bridge.h uses it without declaring it.

elmarco/libvirt,crobinso/libvirt,eskultety/libvirt,jardasgit/libvirt,trainstack/libvirt,olafhering/libvirt,iam-TJ/libvirt,nertpinx/libvirt,taget/libvirt,shugaoye/libvirt,agx/libvirt,eskultety/libvirt,datto/libvirt,zhlcindy/libvirt-1.1.4-maintain,zippy2/libvirt,olafhering/libvirt,siboulet/libvirt-openvz,zippy2/libvirt,iam-TJ/libvirt,taget/libvirt,jfehlig/libvirt,VenkatDatta/libvirt,iam-TJ/libvirt,nertpinx/libvirt,andreabolognani/libvirt,trainstack/libvirt,fabianfreyer/libvirt,eskultety/libvirt,libvirt/libvirt,agx/libvirt,zhlcindy/libvirt-1.1.4-maintain,elmarco/libvirt,jardasgit/libvirt,siboulet/libvirt-openvz,datto/libvirt,bjzhang/libvirt,elmarco/libvirt,shugaoye/libvirt,VenkatDatta/libvirt,jardasgit/libvirt,cbosdo/libvirt,siboulet/libvirt-openvz,elmarco/libvirt,VenkatDatta/libvirt,andreabolognani/libvirt,andreabolognani/libvirt,nertpinx/libvirt,iam-TJ/libvirt,trainstack/libvirt,siboulet/libvirt-openvz,rlaager/libvirt,zippy2/libvirt,zhlcindy/libvirt-1.1.4-maintain,VenkatDatta/libvirt,zhlcindy/libvirt-1.1.4-maintain,jardasgit/libvirt,trainstack/libvirt,cbosdo/libvirt,shugaoye/libvirt,trainstack/libvirt,zippy2/libvirt,jfehlig/libvirt,libvirt/libvirt,olafhering/libvirt,andreabolognani/libvirt,bjzhang/libvirt,agx/libvirt,agx/libvirt,datto/libvirt,cbosdo/libvirt,taget/libvirt,iam-TJ/libvirt,bjzhang/libvirt,datto/libvirt,elmarco/libvirt,agx/libvirt,nertpinx/libvirt,cbosdo/libvirt,rlaager/libvirt,datto/libvirt,nertpinx/libvirt,jardasgit/libvirt,siboulet/libvirt-openvz,shugaoye/libvirt,bjzhang/libvirt,crobinso/libvirt,shugaoye/libvirt,rlaager/libvirt,fabianfreyer/libvirt,trainstack/libvirt,zhlcindy/libvirt-1.1.4-maintain,libvirt/libvirt,jfehlig/libvirt,eskultety/libvirt,rlaager/libvirt,jfehlig/libvirt,eskultety/libvirt,iam-TJ/libvirt,crobinso/libvirt,iam-TJ/libvirt,taget/libvirt,crobinso/libvirt,cbosdo/libvirt,fabianfreyer/libvirt,rlaager/libvirt,bjzhang/libvirt,VenkatDatta/libvirt,trainstack/libvirt,taget/libvirt,olafhering/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,libvirt/libvirt,andreabolognani/libvirt