insane.bbclass: Make ldd exec_prefix error reporting easier to read

insane.bbclass: Make ldd exec_prefix error reporting easier to read

Remove the long obtuse sysroot path from the ldd output.

Make the error message significantly easier to read and understand.

Old Style:
WARNING: QA Issue: keyutils: /home/mhatle/git/oss/oe-core/build-i386/tmp-eglibc/work/i586-oe-linux/keyutils-1.5.5-r1/packages-split/keyutils/sbin/request-key links to something under exec_prefix
WARNING: QA Issue: ldd reports:         libkeyutils.so.1 => /home/mhatle/git/oss/oe-core/build-i386/tmp-eglibc/sysroots/qemux86/usr/lib/libkeyutils.so.1 (0xdead1000)
        libc.so.6 => /home/mhatle/git/oss/oe-core/build-i386/tmp-eglibc/sysroots/qemux86/lib/libc.so.6 (0xdead2000)
        /lib/ld-linux.so.2 => /home/mhatle/git/oss/oe-core/build-i386/tmp-eglibc/sysroots/qemux86/lib/ld-linux.so.2 (0xdead3000)

New style:
WARNING: QA Issue: keyutils: /sbin/request-key, installed in the base_prefix, requires a shared library under exec_prefix (/usr): libkeyutils.so.1 => /usr/lib/libkeyutils.so.1 (0xdead1000)

(From OE-Core rev: 1583a8e2db6dd4843ff45acee458d4924f7d6ced)

Signed-off-by: Mark Hatle <mark.hatle@windriver.com>
Signed-off-by: Elizabeth Flanagan <elizabeth.flanagan@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>