RDMA/cxgb3: Use AF_INET for sin_family field

Elsewhere the sin_family field holds a value with a name of the form
AF_..., so it seems reasonable to do so here as well.  Also the values
of PF_INET and AF_INET are the same.

The Coccinelle semantic patch that makes this change is as follows:

// <smpl>
@@
struct sockaddr_in sip;
@@

(
sip.sin_family ==
- PF_INET
+ AF_INET
|
sip.sin_family !=
- PF_INET
+ AF_INET
|
sip.sin_family =
- PF_INET
+ AF_INET
)
// </smpl>

Signed-off-by: Amitoj Kaur Chawla <amitoj1606@gmail.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>