Merge branch 'bpf-sockmap-sg-api-fixes'

Prashant Bhole says:

====================
These patches fix sg api usage in sockmap. Previously sockmap didn't
use sg_init_table(), which caused hitting BUG_ON in sg api, when
CONFIG_DEBUG_SG is enabled

v1: added sg_init_table() calls wherever needed.

v2:
- Patch1 adds new helper function in sg api. sg_init_marker()
- Patch2 sg_init_marker() and sg_init_table() in appropriate places

Backgroud:
While reviewing v1, John Fastabend raised a valid point about
unnecessary memset in sg_init_table() because sockmap uses sg table
which embedded in a struct. As enclosing struct is zeroed out, there
is unnecessary memset in sg_init_table.

So Daniel Borkmann suggested to define another static inline function
in scatterlist.h which only initializes sg_magic. Also this function
will be called from sg_init_table. From this suggestion I defined a
function sg_init_marker() which sets sg_magic and calls sg_mark_end()
====================

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>