f2fs: change the prototype for show_options

Signed-off-by: Alejandro Martinez Ruiz <alex@nowcomputing.com> (reverted from commit 90295d85c9681e6e983a4bc1808da3c8c3c32370)
REVERT:"f2fs: add code to handle the lack of s_max_links superblock field in 3.2"

further modified for Nexus Grouper Kernel

Signed-off-by: Alejandro Martinez Ruiz <alex@nowcomputing.com>
Signed-off-by: Paul Reioux <reioux@gmail.com> (reverted from commit 207f3dba760f12aa56179b07daaa09b10ec8c554)