x86: numa_32.c: fix sparse warning: Using plain integer as NULL pointer

Fix this sparse warning:

  arch/x86/mm/numa_32.c:197:24: warning: Using plain integer as NULL pointer

Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Cc: trivial@kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
1 file changed