Revert "build: fix cygwin build"
Revert "build: fix cygwin build"

This reverts commit 2d550542ee729c1d9a4d92de344892650817b213.

The patch worked for incremental builds, but broke fresh
builds, because it interfered with automake's automatic
dependency generation.  Until I figure out how to make
automake do what we want, I'd rather leave cygwin broken
but fresh Linux builds working.

rbu/libvirt,andreabolognani/libvirt,elmarco/libvirt,nertpinx/libvirt,libvirt/libvirt,novel/fbsd-libvirt,novel/fbsd-libvirt,elmarco/libvirt,jfehlig/libvirt,VenkatDatta/libvirt,eskultety/libvirt,trainstack/libvirt,bjzhang/libvirt,rlaager/libvirt,VenkatDatta/libvirt,fabianfreyer/libvirt,cbosdo/libvirt,agx/libvirt,elmarco/libvirt,crobinso/libvirt,iam-TJ/libvirt,soulxu/libvirt-xuhj,wiedi/libvirt,usc-isi/libvirt,kantai/libvirt-vfork,emaste/libvirt,iam-TJ/libvirt,trainstack/libvirt,sshah-solarflare/Libvirt-PCI-passthrough-,jardasgit/libvirt,danwent/libvirt-ovs,amery/libvirt-vserver,foomango/libvirt,shugaoye/libvirt,jfehlig/libvirt,novel/fbsd-libvirt,novel/fbsd-libvirt,rlaager/libvirt,leilihh/libvirt,cbosdo/libvirt,fabianfreyer/libvirt,shugaoye/libvirt,rmarwaha/libvirt1,wiedi/libvirt,foomango/libvirt,emaste/libvirt,rlaager/libvirt,rmarwaha/libvirt,trainstack/libvirt,rmarwaha/libvirt1,andreabolognani/libvirt,rlaager/libvirt,fabianfreyer/libvirt,rmarwaha/libvirt,taget/libvirt,fabianfreyer/libvirt,warewolf/libvirt,dumbbell/libvirt,zhlcindy/libvirt-1.1.4-maintain,iam-TJ/libvirt,rbu/libvirt,fabianfreyer/libvirt,eskultety/libvirt,wiedi/libvirt,emaste/libvirt,iam-TJ/libvirt,bjzhang/libvirt,zhlcindy/libvirt-1.1.4-maintain,VenkatDatta/libvirt,jardasgit/libvirt,shugaoye/libvirt,wiedi/libvirt,leilihh/libvirt,crobinso/libvirt,warewolf/libvirt,leilihh/libvirt,nertpinx/libvirt,jardasgit/libvirt,sshah-solarflare/Libvirt-PCI-passthrough-,nertpinx/libvirt,foomango/libvirt,novel/fbsd-libvirt,rbu/libvirt,eskultety/libvirt,iam-TJ/libvirt,usc-isi/libvirt,usc-isi/libvirt,libvirt/libvirt,crobinso/libvirt,rlaager/libvirt,trainstack/libvirt,olafhering/libvirt,trainstack/libvirt,rmarwaha/libvirt,jfehlig/libvirt,jeckersb/libvirt,datto/libvirt,bjzhang/libvirt,leilihh/libvirt,andreabolognani/libvirt,cbosdo/libvirt,kantai/libvirt-vfork,usc-isi/libvirt,warewolf/libvirt,zippy2/libvirt,zhlcindy/libvirt-1.1.4-maintain,iam-TJ/libvirt,dumbbell/libvirt,kantai/libvirt-vfork,novel/fbsd-libvirt,datto/libvirt,siboulet/libvirt-openvz,datto/libvirt,dumbbell/libvirt,iam-TJ/libvirt,emaste/libvirt,taget/libvirt,trainstack/libvirt,andreabolognani/libvirt,jfehlig/libvirt,nertpinx/libvirt,zippy2/libvirt,sshah-solarflare/Libvirt-PCI-passthrough-,datto/libvirt,emaste/libvirt,rmarwaha/libvirt,soulxu/libvirt-xuhj,foomango/libvirt,rmarwaha/libvirt1,siboulet/libvirt-openvz,emaste/libvirt,foomango/libvirt,shugaoye/libvirt,nertpinx/libvirt,cbosdo/libvirt,taget/libvirt,emaste/libvirt,andreabolognani/libvirt,elmarco/libvirt,siboulet/libvirt-openvz,sshah-solarflare/Libvirt-PCI-passthrough-,wiedi/libvirt,jeckersb/libvirt,danwent/libvirt-ovs,rbu/libvirt,rmarwaha/libvirt1,warewolf/libvirt,taget/libvirt,agx/libvirt,taget/libvirt,usc-isi/libvirt,sshah-solarflare/Libvirt-PCI-passthrough-,wiedi/libvirt,olafhering/libvirt,jeckersb/libvirt,agx/libvirt,rmarwaha/libvirt,libvirt/libvirt,jeckersb/libvirt,VenkatDatta/libvirt,rmarwaha/libvirt1,novel/fbsd-libvirt,trainstack/libvirt,wiedi/libvirt,VenkatDatta/libvirt,zippy2/libvirt,warewolf/libvirt,olafhering/libvirt,jeckersb/libvirt,bjzhang/libvirt,soulxu/libvirt-xuhj,danwent/libvirt-ovs,rbu/libvirt,soulxu/libvirt-xuhj,novel/fbsd-libvirt,warewolf/libvirt,jeckersb/libvirt,jardasgit/libvirt,agx/libvirt,dumbbell/libvirt,rmarwaha/libvirt1,jeckersb/libvirt,jardasgit/libvirt,danwent/libvirt-ovs,bjzhang/libvirt,leilihh/libvirt,shugaoye/libvirt,amery/libvirt-vserver,olafhering/libvirt,libvirt/libvirt,dumbbell/libvirt,zhlcindy/libvirt-1.1.4-maintain,eskultety/libvirt,rmarwaha/libvirt,amery/libvirt-vserver,siboulet/libvirt-openvz,kantai/libvirt-vfork,crobinso/libvirt,siboulet/libvirt-openvz,kantai/libvirt-vfork,zippy2/libvirt,agx/libvirt,dumbbell/libvirt,danwent/libvirt-ovs,cbosdo/libvirt,zhlcindy/libvirt-1.1.4-maintain,leilihh/libvirt,eskultety/libvirt,datto/libvirt,amery/libvirt-vserver,amery/libvirt-vserver,novel/fbsd-libvirt,warewolf/libvirt,soulxu/libvirt-xuhj,elmarco/libvirt