af_packet: refactor error handling to avoid NULL pointer dereference

af_packet: refactor error handling to avoid NULL pointer dereference

Coverity CID # 13321

Checking *internals != NULL before accessing req is not good enough,
because **internals is a function argument and the function doesn't
really know what is passed-in.  We can close our eyes and ignore the
warning on the basis of controlling all the calling code, or we can
refactor the error exit to avoid the issue entirely...

Signed-off-by: John W. Linville <linville@tuxdriver.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>