qemu: replace VIR_FREE with g_free in qemuFirmware*FreeContent()
qemu: replace VIR_FREE with g_free in qemuFirmware*FreeContent()

These functions are all only called as a part of qemuFirmwareFree(),
which frees the qemuFirmware object before return, so we can be sure
none of the pointers is referenced after freeing (and thus there is no
need to clear any of them).

Signed-off-by: Laine Stump <c23361c43fbf79fed83e8b76173707b083d6caf5@redhat.com>
Reviewed-by: Daniel Henrique Barboza <627b089ad62deae9aaf06ccfa2c9056df28927e0@gmail.com>

nertpinx/libvirt,zippy2/libvirt,zippy2/libvirt,crobinso/libvirt,libvirt/libvirt,nertpinx/libvirt,zippy2/libvirt,crobinso/libvirt,olafhering/libvirt,jfehlig/libvirt,libvirt/libvirt,libvirt/libvirt,crobinso/libvirt,libvirt/libvirt,olafhering/libvirt,olafhering/libvirt,nertpinx/libvirt,nertpinx/libvirt,crobinso/libvirt,nertpinx/libvirt,jfehlig/libvirt,jfehlig/libvirt,olafhering/libvirt,zippy2/libvirt,jfehlig/libvirt