storage: Fix a resource leak in storageVolCreateXML
storage: Fix a resource leak in storageVolCreateXML

Commit id '1b5685da' refactored the code to move buildvoldef inside
the buildVol conditional; however, the VIR_FREE of the memory was
left only when 'buildret' failed, thus we're leaking memory.

Signed-off-by: John Ferlan <87558058f6f829e5ec976c8ef960720af4ff9c7d@redhat.com>

datto/libvirt,libvirt/libvirt,olafhering/libvirt,crobinso/libvirt,rlaager/libvirt,libvirt/libvirt,zippy2/libvirt,andreabolognani/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,andreabolognani/libvirt,datto/libvirt,jfehlig/libvirt,crobinso/libvirt,nertpinx/libvirt,jfehlig/libvirt,jardasgit/libvirt,andreabolognani/libvirt,rlaager/libvirt,taget/libvirt,VenkatDatta/libvirt,jardasgit/libvirt,VenkatDatta/libvirt,nertpinx/libvirt,crobinso/libvirt,jfehlig/libvirt,nertpinx/libvirt,datto/libvirt,rlaager/libvirt,VenkatDatta/libvirt,eskultety/libvirt,datto/libvirt,olafhering/libvirt,taget/libvirt,taget/libvirt,taget/libvirt,zippy2/libvirt,eskultety/libvirt,rlaager/libvirt,VenkatDatta/libvirt,zippy2/libvirt,VenkatDatta/libvirt,fabianfreyer/libvirt,olafhering/libvirt,jardasgit/libvirt,eskultety/libvirt,libvirt/libvirt,crobinso/libvirt,rlaager/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,eskultety/libvirt,eskultety/libvirt,andreabolognani/libvirt,jardasgit/libvirt,olafhering/libvirt,nertpinx/libvirt,zippy2/libvirt,andreabolognani/libvirt,jfehlig/libvirt,jardasgit/libvirt,taget/libvirt,datto/libvirt,libvirt/libvirt