Clear errno before call to strtol(3).

Since strtol(3) doesn't clear errno on success, anything that sets
errno prior to this call will make it look like the call failed. This
happens when built with ASAN.

Signed-off-by: Dan Albert <[email protected]>
Acked-by: Steve Lawrence <[email protected]>

Author: DanAlbert

checkpolicy/checkpolicy.c

@@ -456,7 +456,9 @@ int main(int argc, char **argv)
 			mlspol = 1;
 			break;
 		case 'c':{
-				long int n = strtol(optarg, NULL, 10);
+				long int n;
+				errno = 0;
+				n = strtol(optarg, NULL, 10);
 				if (errno) {
 					fprintf(stderr,
 						"Invalid policyvers specified: %s\n",