perf tools: Finish the removal of 'self' arguments

They convey no information, perhaps I was bitten by some snake at some
point, complete the detox by naming the last of those arguments more
sensibly.

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: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-u1r0dnjoro08dgztiy2g3t2q@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/pstack.h b/tools/perf/util/pstack.h
index 4cedea5..c3cb658 100644
--- a/tools/perf/util/pstack.h
+++ b/tools/perf/util/pstack.h
@@ -5,10 +5,10 @@
 
 struct pstack;
 struct pstack *pstack__new(unsigned short max_nr_entries);
-void pstack__delete(struct pstack *self);
-bool pstack__empty(const struct pstack *self);
-void pstack__remove(struct pstack *self, void *key);
-void pstack__push(struct pstack *self, void *key);
-void *pstack__pop(struct pstack *self);
+void pstack__delete(struct pstack *pstack);
+bool pstack__empty(const struct pstack *pstack);
+void pstack__remove(struct pstack *pstack, void *key);
+void pstack__push(struct pstack *pstack, void *key);
+void *pstack__pop(struct pstack *pstack);
 
 #endif /* _PERF_PSTACK_ */