octeontx2-pf: remove unused variables req_hdr and rsp_hdr

Clang static checker(scan-buid):
drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c:503:2: warning:
Value stored to 'rsp_hdr' is never read [deadcode.DeadStores]

Remove these unused variables to save some space.

Signed-off-by: Su Hui <suhui@nfschina.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240328020723.4071539-1-suhui@nfschina.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>