It looks like it installed fine. At least, I don't see any errors. What makes you thing that tcpdump will automatically pick up the new libpcap that you just installed? On my system (Fedora), tcpdump is not dynamically linked to libpcap.
Code:
[todd@perl todd]$ ldd /usr/sbin/tcpdump
libc.so.6 => /lib/tls/libc.so.6 (0x00aef000)
/lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x0038c000)
Also note that on some systems /usr/local/lib is not part of the path when searching for dynamic libraries. I've had to add that directory to /etc/ld.so.conf.
Even if tcpdump were dynamically linked and ld.so.conf was properly configured, it still may not pick up the new libpcap because the version numbers are quite different. You have no assurance that those libraries are binary compatible.
My advice is to rebuild tcpdump and have it link to the new libpcap.