This patch fixes actually two issues with 'make cscope'.

Firstly, it fixes the command for MacOS "find" command as MacOS will append the
full path of "$(SRC_PATH)/" before each found entry, then after the final "./"
replacement trick it'll look like (e.g., "qapi/qmp-dispatch.c"):

  /qapi/qmp-dispatch.c

Which will point to the root directory instead.

Fix it by simply remove the "/" in "$(SRC_PATH)/" of "find-src-path", then
it'll work for at least both Linux and MacOS.

The other OS-independent issue is to start proactively ignoring soft links when
generating tags, otherwise by default on master branch we'll see this error
when "make cscope":

cscope: cannot find file subprojects/libvhost-user/include/atomic.h

This patch should fix the two issues altogether.

Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20210804132328.41353-3-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>