README.md: fix broken link to stacksnoop examples
README.md: fix broken link to stacksnoop examples

shodoco/bcc,shodoco/bcc,shodoco/bcc,iovisor/bcc,romain-intel/bcc,brendangregg/bcc,brendangregg/bcc,tuxology/bcc,mcaleavya/bcc,romain-intel/bcc,tuxology/bcc,tuxology/bcc,iovisor/bcc,iovisor/bcc,mcaleavya/bcc,romain-intel/bcc,romain-intel/bcc,brendangregg/bcc,brendangregg/bcc,iovisor/bcc,brendangregg/bcc,tuxology/bcc,romain-intel/bcc,tuxology/bcc,mcaleavya/bcc,iovisor/bcc,shodoco/bcc,shodoco/bcc,mcaleavya/bcc,mcaleavya/bcc