util: uuid: remove use of virHexToBin
util: uuid: remove use of virHexToBin

Prefer g_ascii_xdigit_value to virHexToBin.

Check the return value of the function and
remove the g_ascii_isxdigit calls, since
they're done anyway internally.

Signed-off-by: Ján Tomko <4cab11cfb98d3c937327354a78eb07dbb6ee2bc6@redhat.com>
Reviewed-by: Laine Stump <c23361c43fbf79fed83e8b76173707b083d6caf5@redhat.com>

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