0122-vmstat: getopt*() returns -1 when done, not EOF.

Luckily, EOF is usually -1, but this is not guaranteed by the standard.

Signed-off-by: Craig Small <csmall@enc.com.au>

vmstat.c

@@ -910,7 +910,7 @@ int main(int argc, char *argv[])
     atexit(close_stdout);
 
     while ((c =
-        getopt_long(argc, argv, "afmnsdDp:S:wthV", longopts, NULL)) != EOF)
+        getopt_long(argc, argv, "afmnsdDp:S:wthV", longopts, NULL)) != -1)
         switch (c) {
         case 'V':
             printf(PROCPS_NG_VERSION);