affs: kstrdup() memory handling

There is a possibility of kstrdup() failure upon memory pressure.
Therefore, returning ENOMEM even for new_opts.

[akpm@linux-foundation.org: cleanup]
Signed-off-by: Sanidhya Kashyap <sanidhya.gatech@gmail.com>
Cc: Taesoo kim <taesoo@gatech.edu>
Cc: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>