libsysprof-capture: add sysprof_collector_log_printf()

This is a convenience function to call sysprof_collector_log() while also
formatting the message.

Ideally we'd be able to avoid the string format if we are not currently
collecting data, but that can be left for a future commit. We don't have
recursive locks so we need to duplicate the structure setup.

src/libsysprof-capture/sysprof-collector.c

@@ -454,3 +454,19 @@ sysprof_collector_log (GLogLevelFlags  severity,
 
   } COLLECTOR_END;
 }
+
+void
+sysprof_collector_log_printf (GLogLevelFlags  severity,
+                              const gchar    *domain,
+                              const gchar    *format,
+                              ...)
+{
+  g_autofree gchar *formatted = NULL;
+  va_list args;
+
+  va_start (args, format);
+  formatted = g_strdup_vprintf (format, args);
+  va_end (args);
+
+  sysprof_collector_log (severity, domain, formatted);
+}

src/libsysprof-capture/sysprof-collector.h

@@ -81,5 +81,10 @@ SYSPROF_AVAILABLE_IN_3_36
 void sysprof_collector_log      (GLogLevelFlags         severity,
                                  const gchar           *domain,
                                  const gchar           *message);
+SYSPROF_AVAILABLE_IN_3_38
+void sysprof_collector_log_printf (GLogLevelFlags         severity,
+                                   const gchar           *domain,
+                                   const gchar           *format,
+                                   ...) G_GNUC_PRINTF (3, 4);
 
 G_END_DECLS