pmdaresctrl: add indom help text for LLC

Drop a leftover in the expected QA test output for resctrl,
and use latest PMDA interface (this PMDA only uses the fetch
callback, this'll be fine as long as that remains the case).
Also name the default PMDA log file with the updated name.

qa/655.out

@@ -1,7 +1,6 @@
 QA output created by 655
 
 === resctrl agent installation ===
-newhelp: [<stdin>:33] RPM.0: Unknown metric name, entry abandoned
 Updating the Performance Metrics Name Space (PMNS) ...
 Terminate PMDA if already installed ...
 [...install files, make output...]

src/pmdas/resctrl/help

@@ -27,6 +27,8 @@
 # blank lines before the @ line are ignored
 #
 
+@ 159.0 set of last level caches (LLC)
+
 @ resctrl.llc.occupancy % of LLC in use
 @ resctrl.llc.mbm_local local memory bandwidth of this LLC
 @ resctrl.llc.mbm_total total memory bandwidth of this LLC

src/pmdas/resctrl/resctrl.c

@@ -248,7 +248,7 @@ resctrl_init(pmdaInterface *dp)
 	int sep = pmPathSeparator();
 	pmsprintf(mypath, sizeof(mypath), "%s%c" "resctrl" "%c" "help",
 		pmGetConfig("PCP_PMDAS_DIR"), sep, sep);
-	pmdaDSO(dp, PMDA_INTERFACE_6, "llc DSO", mypath);
+	pmdaDSO(dp, PMDA_INTERFACE_LATEST, "resctrl DSO", mypath);
     } else {
 	pmSetProcessIdentity(username);
     }
@@ -279,8 +279,8 @@ main(int argc, char **argv)
 
     pmsprintf(mypath, sizeof(mypath), "%s%c" "resctrl" "%c" "help",
 		pmGetConfig("PCP_PMDAS_DIR"), sep, sep);
-    pmdaDaemon(&dispatch, PMDA_INTERFACE_6, pmGetProgname(), RESCTRL,
-		"llc.log", mypath);
+    pmdaDaemon(&dispatch, PMDA_INTERFACE_LATEST, pmGetProgname(), RESCTRL,
+		"resctrl.log", mypath);
 
     pmdaGetOptions(argc, argv, &opts, &dispatch);
     if (opts.errors) {