lib/, src/: Replace strtou[l]l(3) by strtou[l]l_noneg()

strtou[l]l(3) silently converts negative numbers into positive.  This
behavior is wrong: a negative value should be parsed as a negative
value, which would underflow unsigned (long) long, and so would return
the smallest possible value, 0, and set errno to ERANGE to report an
error.

Reviewed-by: Iker Pedrosa <ipedrosa@redhat.com>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

src/check_subid_range.c

@@ -12,6 +12,8 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
+
+#include "atoi/strtou_noneg.h"
 #include "defines.h"
 #include "prototypes.h"
 #include "subordinateio.h"
@@ -35,10 +37,10 @@ int main(int argc, char **argv)
 	owner = argv[1];
 	check_uids = argv[2][0] == 'u';
 	errno = 0;
-	start = strtoul(argv[3], NULL, 10);
+	start = strtoul_noneg(argv[3], NULL, 10);
 	if (errno != 0)
 		exit(1);
-	count = strtoul(argv[4], NULL, 10);
+	count = strtoul_noneg(argv[4], NULL, 10);
 	if (errno != 0)
 		exit(1);
 	if (check_uids) {