octeontx2: hide unused label

octeontx2: hide unused label

A previous patch introduces a build-time warning when CONFIG_DCB
is disabled:

drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c: In function 'otx2_probe':
drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c:3217:1: error: label 'err_free_zc_bmap' defined but not used [-Werror=unused-label]
drivers/net/ethernet/marvell/octeontx2/nic/otx2_vf.c: In function 'otx2vf_probe':
drivers/net/ethernet/marvell/octeontx2/nic/otx2_vf.c:740:1: error: label 'err_free_zc_bmap' defined but not used [-Werror=unused-label]

Add the same #ifdef check around it.

Fixes: efabce290151 ("octeontx2-pf: AF_XDP zero copy receive support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Suman Ghosh <sumang@marvell.com>
Link: https://patch.msgid.link/20250219162239.1376865-1-arnd@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>