tools lib traceevent: Fix processing of dereferenced args in bprintk events

tools lib traceevent: Fix processing of dereferenced args in bprintk events

In the case that a bprintk event has a dereferenced pointer that is
stored as a string, and there's more values to process (more args), the
arg was not updated to point to the next arg after processing the
dereferenced pointer, and it screwed up what was to be displayed.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-trace-devel@vger.kernel.org
Cc: stable@vger.kernel.org
Fixes: 37db96bb49629 ("tools lib traceevent: Handle new pointer processing of bprint strings")
Link: http://lkml.kernel.org/r/20181210134522.3f71e2ca@gandalf.local.home
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>