qed: Fix a memory allocation failure test in 'qed_mcp_cmd_init()'

We allocate 'p_info->mfw_mb_cur' and 'p_info->mfw_mb_shadow' but we check
'p_info->mfw_mb_addr' instead of 'p_info->mfw_mb_cur'.

'p_info->mfw_mb_addr' is never 0, because it is initiliazed a few lines
above in 'qed_load_mcp_offsets()'.

Update the test and check the result of the 2 'kzalloc()' instead.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Tomer Tayar <Tomer.Tayar@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>