storage: avoid memory leak on stat failure
storage: avoid memory leak on stat failure

Spotted by coverity.  Triggers on failed stat, although I'm not sure
how easy that condition is, so I'm not sure if this is a runtime
memory hog.  Regression introduced in commit 8077d64 (unreleased).

* src/util/storage_file.c (virStorageFileGetMetadataFromFD):
Reduce need for malloc, avoiding a leak.

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