snort: avoid detecting the host pcre

snort: avoid detecting the host pcre

The pcre configure script does this:

if test "x$with_libpcre_libraries" != "xno"; then
    LDFLAGS="${LDFLAGS}  -L${with_libpcre_libraries}"
else
    LDFLAGS="${LDFLAGS} `pcre-config --libs`"
fi

So if you don't pass --with-libpcre-libraries, it calls pcre-config as
available in the PATH. So it picks up pcre-config from $(HOST_DIR) or
the system, which return results inappropriate for cross-compilation.

So, let's explicitly pass --with-libpcre-includes and
--with-libpcre-libraries to avoid those issues.

Fixes:

  http://autobuild.buildroot.net/results/3df11c48c8e2f795f478d1ee666dda9de19133d0/

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>