Fix these sparse warnings:
  arch/x86/kernel/machine_kexec_32.c:124:22: warning: Using plain integer as NULL pointer
  arch/x86/kernel/traps.c:950:24: 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>
 static void machine_kexec_prepare_page_tables(struct kimage *image)
 {
        void *control_page;
-       pmd_t *pmd = 0;
+       pmd_t *pmd = NULL;
 
        control_page = page_address(image->control_code_page);
 #ifdef CONFIG_X86_PAE
 
        info.si_signo = SIGILL;
        info.si_errno = 0;
        info.si_code = ILL_BADSTK;
-       info.si_addr = 0;
+       info.si_addr = NULL;
        if (notify_die(DIE_TRAP, "iret exception",
                        regs, error_code, 32, SIGILL) == NOTIFY_STOP)
                return;