insane: Don't try to run objdump on symlinks

insane: Don't try to run objdump on symlinks

If the link is absolute then we might end up reading from a host binary
or a nonexistent path, neither of which will produce useful results and
may result in objdump failure and python backtrace spew.  If the link
does point to a binary within the installation root then we will scan the
pointed-to file at some point anyway so there is no need to do it again.

(From OE-Core rev: 91769af1c1175ac9bb43d16d05fb1c8736dd9287)

Signed-off-by: Phil Blundell <pb@pbcl.net>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>