xfs: make xfs_free_eofblocks() non-static, return EAGAIN on trylock failure

Turn xfs_free_eofblocks() into a non-static function, return EAGAIN to
indicate trylock failure and make sure this error is not propagated in
xfs_release().

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

diff --git a/fs/xfs/xfs_vnodeops.h b/fs/xfs/xfs_vnodeops.h
index 447e146..52fafc4 100644
--- a/fs/xfs/xfs_vnodeops.h
+++ b/fs/xfs/xfs_vnodeops.h
@@ -57,5 +57,6 @@
 int xfs_wait_on_pages(struct xfs_inode *ip, xfs_off_t first, xfs_off_t last);
 
 int xfs_zero_eof(struct xfs_inode *, xfs_off_t, xfs_fsize_t);
+int xfs_free_eofblocks(struct xfs_mount *, struct xfs_inode *, bool);
 
 #endif /* _XFS_VNODEOPS_H */