Factor out some of the duplicated code in the symbol lookup functions, in
preparation for adding userland CTF support to DTrace.

MFC after:	1 month
Sponsored by:	EMC / Isilon Storage Division


git-svn-id: svn+ssh://svn.freebsd.org/base/head@272125 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
reiserfs: Use signed i_nlink

Unlike Linux, FreeBSD's kernel doesn't like unsigned file link
count. This is consistent with our ext2fs implementation.

MFC after:	1 month


git-svn-id: svn+ssh://svn.freebsd.org/base/head@272126 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f