[PATCH] NFS: __nfs_revalidate_inode() can use "inode" before checking it is non-NULL

The "!inode" check in __nfs_revalidate_inode() occurs well after the first
time it is dereferenced, so get rid of it.

Coverity: #cid 1372, 1373

Test plan:
Code review; recheck with Coverity.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>