[PATCH bpf] bpf: do not use kmalloc_nolock when !HAVE_CMPXCHG_DOUBLE

[kernel test robot]

Hi Levi,

kernel test robot noticed the following build warnings:

[auto build test WARNING on e06e6b8001233241eb5b2e2791162f0585f50f4b]

url:    https://github.com/intel-lab-lkp/linux/commits/Levi-Zim-via-B4-Relay/bpf-do-not-use-kmalloc_nolock-when-HAVE_CMPXCHG_DOUBLE/20260314-195705
base:   e06e6b8001233241eb5b2e2791162f0585f50f4b
patch link:    https://lore.kernel.org/r/20260314-bpf-kmalloc-nolock-v1-1-24abf3f75a9f%40outlook.com
patch subject: [PATCH bpf] bpf: do not use kmalloc_nolock when !HAVE_CMPXCHG_DOUBLE
config: x86_64-rhel-9.4 (https://download.01.org/0day-ci/archive/20260314/202603141857.sLJ0vJoa-lkp@intel.com/config)
compiler: gcc-14 (Debian 14.2.0-19) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260314/202603141857.sLJ0vJoa-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp at intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202603141857.sLJ0vJoa-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from include/net/bpf_sk_storage.h:15,
                    from net/core/sock.c:141:
>> include/linux/bpf_local_storage.h:22:19: warning: 'KMALLOC_NOLOCK_SUPPORTED' defined but not used [-Wunused-const-variable=]
      22 | static const bool KMALLOC_NOLOCK_SUPPORTED = IS_ENABLED(CONFIG_HAVE_CMPXCHG_DOUBLE);
         |                   ^~~~~~~~~~~~~~~~~~~~~~~~


vim +/KMALLOC_NOLOCK_SUPPORTED +22 include/linux/bpf_local_storage.h

    21	
  > 22	static const bool KMALLOC_NOLOCK_SUPPORTED = IS_ENABLED(CONFIG_HAVE_CMPXCHG_DOUBLE);
    23	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki