tools/power turbostat: option '-n' is ambiguous

In some cases specifying the '-n' command line argument will cause
turbostat to fail.  For instance 'turbostat -n 1' works fine; however,
'turbostat -n 1 -d' will fail.  This is the result of the first call
to getopt_long_only() where "MP" is specified as the optstring.  This can
be easily fixed by changing the optstring from "MP" to "MPn:" to remove
ambiguity between the arguments.

tools/power turbostat: option '-n' is ambiguous; possibilities: '-num_iterations' '-no-msr' '-no-perf'

Fixes: a0e86c9 ("tools/power turbostat: Add --no-perf option")

Signed-off-by: David Arcari <darcari@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>

tools/power/x86/turbostat/turbostat.c

@@ -8424,7 +8424,7 @@ void cmdline(int argc, char **argv)
  * Parse some options early, because they may make other options invalid,
  * like adding the MSR counter with --add and at the same time using --no-msr.
  */
- while ((opt = getopt_long_only(argc, argv, "MP", long_options, &option_index)) != -1) {
+ while ((opt = getopt_long_only(argc, argv, "MPn:", long_options, &option_index)) != -1) {
  switch (opt) {
  case 'M':
  no_msr = 1;