Compilation Error in hplip-3.19.6: hppsfilter.c

When attempting to build hplip-3.19.6 using the ebuild from gentoo, there is a compilation error in prnt/hpcups/hppsfilter.c :

prnt/hpps/hppsfilter.c:107:13: error: void function 'open_tempbookletfile' should not return a value
      [-Wreturn-type]
            return 1;
            ^ ~

This is a simple error in which a void function is attempting to return a value. I've attached a patch which fixes the issue and allows hplip to successfully build using emerge.

Gentoo ebuild:
https://gitweb.gentoo.org/repo/gentoo.git/tree/net-print/hplip/hplip-3.19.6.ebuild