The nvidia-drivers-pax-const.patch fails with x11-drivers/nvidia-drivers-325.15 The way how nvidia registers has changed in this version, and it seems (due to code inspection and testing on x86 and amd64) that this patch is not longer necessary and could (and should) just be removed from the ebuild. This remark holds only for nvidia-drivers-pax-const.patch The other corresponding patch (nvidia-drivers-pax-usercopy.patch) still applies without problems (and still should be applied).
Fixed without a revision bump. Thanks for the report.