[PATCH] converts a for (i = 0 ; i < NR_CPUS ; i++) to for_each_cpu(i)  in 
files_defer_init().

The comment 'Really early - can't use for_each_cpu' is probably outdated, 
because if we access &per_cpu(fdtable_defer_list, cpu), then for_each_cpu() or 
cpu_possible() should be available (It was available at setup_per_cpu_areas() 
time)

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>