net: mvpp2: Return correct error codes

The return value of kzalloc on failure of allocation of memory should
be -ENOMEM and not -1.

Found using Coccinelle. A simplified version of the semantic patch
used is:

//<smpl>
@@
expression *e;
position p,q;
@@

e@q = kzalloc(...);
if@p (e == NULL) {
...
return
- -1
+ -ENOMEM
;
}
//</smpl>

This function may also return -1 after calling mpp2_prs_tcam_port_map_get.
So that the function consistently returns meaningful error values on
failure, the -1 is changed to -EINVAL.

Signed-off-by: Amitoj Kaur Chawla <amitoj1606@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>