mirror://sourceforge.net/dxr3/em8300-0.16.0.tar.gz is not valid, should be mirror://sourceforge/ only... Also, that || die "emake install failed." spanning across two lines without any \ is a bit nasty... Please fix, thanks.
http://sources.gentoo.org/viewcvs.py/gentoo-x86/media-video/em8300-libraries/em8300-libraries-0.16.0.ebuild?r1=1.1&r2=1.2 FIXED.