Take dump_stacktrace into use

MaxScale and tests now both use the same code to dump stacktraces.

maxscale-system-test/testconnections.cpp

@@ -8,12 +8,15 @@
 #include <execinfo.h>
 #include <sys/stat.h>
 #include <sstream>
+#include <maxbase/stacktrace.hh>
 
 #include "mariadb_func.h"
 #include "maxadmin_operations.h"
 #include "sql_t1.h"
 #include "testconnections.h"
 
+using namespace mxb;
+
 namespace maxscale
 {
 static bool start = true;
@@ -37,9 +40,7 @@ static void signal_set(int sig, void (*handler)(int))
 
 void sigfatal_handler(int i)
 {
-    void *addrs[128];
-    int count = backtrace(addrs, 128);
-    backtrace_symbols_fd(addrs, count, STDERR_FILENO);
+    dump_stacktrace();
     signal_set(i, SIG_DFL);
     raise(i);
 }