libpcap: update to 1.3.0

Disabled canusb by setting ac_cv_header_libusb_1_0_libusb_h to no in
Makefile.  Upstream configure script ignores --disable-canusb.

Signed-off-by: Russell Senior <russell@personaltelco.net>

git-svn-id: svn://svn.openwrt.org/openwrt@36150 3c298f89-4303-0410-b956-a3cf2f4a3e73
libpcap: get rid of some bloat introduced by the update

git-svn-id: svn://svn.openwrt.org/openwrt@36151 3c298f89-4303-0410-b956-a3cf2f4a3e73