In vnode_pager_generic_getpages() vp->v_mount is dereferenced in the
beginning, thus can't be NULL.

Sponsored by:	Nginx, Inc.


git-svn-id: svn+ssh://svn.freebsd.org/base/head@274715 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f