tools/x86/kcpuid: Check last token too

Input lines like

  0x8000001E,     0, EAX,   31:0, Extended APIC ID

where the short name is missing lead to a segfault because the loop
takes the long name for the short name and tokens[5] becomes NULL which
explodes later in strcpy().

Check its value too before further processing.

Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Feng Tang <feng.tang@intel.com>
Link: https://lkml.kernel.org/r/20210315125901.30315-1-bp@alien8.de

tools/arch/x86/kcpuid/kcpuid.c

@@ -324,6 +324,8 @@ static int parse_line(char *line)
 		str = NULL;
 	}
 	tokens[5] = strtok(str, "\n");
+	if (!tokens[5])
+		goto err_exit;
 
 	/* index/main-leaf */
 	index = strtoull(tokens[0], NULL, 0);