util: perf: use VIR_AUTOFREE instead of VIR_FREE for scalar types

By making use of GNU C's cleanup attribute handled by the
VIR_AUTOFREE macro for declaring scalar variables, majority
of the VIR_FREE calls can be dropped, which in turn leads to
getting rid of most of our cleanup sections.
Signed-off-by: NSukrit Bhatnagar <skrtbhtngr@gmail.com>
Reviewed-by: NErik Skultety <eskultet@redhat.com>

src/util/virperf.c

@@ -175,12 +175,12 @@ typedef struct virPerfEventAttr *virPerfEventAttrPtr;
 static int
 virPerfRdtAttrInit(void)
 {
-    char *buf = NULL;
     char *tmp = NULL;
     unsigned int attr_type = 0;
+    VIR_AUTOFREE(char *) buf = NULL;
 
     if (virFileReadAllQuiet("/sys/devices/intel_cqm/type", 10, &buf) < 0)
-        goto error;
+        return -1;
 
     if ((tmp = strchr(buf, '\n')))
         *tmp = '\0';
@@ -188,19 +188,14 @@ virPerfRdtAttrInit(void)
     if (virStrToLong_ui(buf, NULL, 10, &attr_type) < 0) {
         virReportSystemError(errno, "%s",
                              _("failed to get rdt event type"));
-        goto error;
+        return -1;
     }
-    VIR_FREE(buf);
 
     attrs[VIR_PERF_EVENT_CMT].attrType = attr_type;
     attrs[VIR_PERF_EVENT_MBMT].attrType = attr_type;
     attrs[VIR_PERF_EVENT_MBML].attrType = attr_type;
 
     return 0;
-
- error:
-    VIR_FREE(buf);
-    return -1;
 }
 
 
@@ -209,7 +204,6 @@ virPerfEventEnable(virPerfPtr perf,
                    virPerfEventType type,
                    pid_t pid)
 {
-    char *buf = NULL;
     struct perf_event_attr attr;
     virPerfEventPtr event = &(perf->events[type]);
     virPerfEventAttrPtr event_attr = &attrs[type];
@@ -227,6 +221,8 @@ virPerfEventEnable(virPerfPtr perf,
     }
 
     if (type == VIR_PERF_EVENT_CMT) {
+        VIR_AUTOFREE(char *) buf = NULL;
+
         if (virFileReadAll("/sys/devices/intel_cqm/events/llc_occupancy.scale",
                            10, &buf) < 0)
             goto error;
@@ -236,8 +232,6 @@ virPerfEventEnable(virPerfPtr perf,
                                  _("failed to get cmt scaling factor"));
             goto error;
         }
-
-        VIR_FREE(buf);
     }
 
     memset(&attr, 0, sizeof(attr));
@@ -268,7 +262,6 @@ virPerfEventEnable(virPerfPtr perf,
 
  error:
     VIR_FORCE_CLOSE(event->fd);
-    VIR_FREE(buf);
     return -1;
 }