ethernet: Remove unnecessary alloc/OOM messages, alloc cleanups

alloc failures already get standardized OOM
messages and a dump_stack.

Convert kzalloc's with multiplies to kcalloc.
Convert kmalloc's with multiplies to kmalloc_array.
Fix a few whitespace defects.
Convert a constant 6 to ETH_ALEN.
Use parentheses around sizeof.
Convert vmalloc/memset to vzalloc.
Remove now unused size variables.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>