perf tools: Introduce zfree

For the frequent idiom of:

   free(ptr);
   ptr = NULL;

Make it expect a pointer to the pointer being freed, so that it becomes
clear at first sight that the variable being freed is being modified.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-pfw02ezuab37kha18wlut7ir@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 2 insertions, 4 deletions

diff --git a/tools/perf/ui/browser.c b/tools/perf/ui/browser.c
index 94223d404f43..d11541d4d7d7 100644
--- a/tools/perf/ui/browser.c
+++ b/tools/perf/ui/browser.c
@@ -256,8 +256,7 @@ int ui_browser__show(struct ui_browser *browser, const char *title,
         __ui_browser__show_title(browser, title);
 
         browser->title = title;
-        free(browser->helpline);
-        browser->helpline = NULL;
+        zfree(&browser->helpline);
 
         va_start(ap, helpline);
         err = vasprintf(&browser->helpline, helpline, ap);
@@ -272,8 +271,7 @@ void ui_browser__hide(struct ui_browser *browser)
 {
         pthread_mutex_lock(&ui__lock);
         ui_helpline__pop();
-        free(browser->helpline);
-        browser->helpline = NULL;
+        zfree(&browser->helpline);
         pthread_mutex_unlock(&ui__lock);
 }