bnx2x: correct a comment mistake in grammar

It is not right in grammar to spell "Its not". The right one is "It's
not".

And this line is also over 80 characters. So I broke it into two lines
as well in order to make that line not be more than 80 characters.

Signed-off-by: Hu Haowen <xianfengting221@163.com>
Signed-off-by: David S. Miller <davem@davemloft.net>