fix pointer style to match the style guide

We do this in a lot of places, but we're inconsistent.
Normalize the code to the Google C++ style guide.

Change-Id: Ic2aceab661ce8f6b993dda21b1cdf5d2198dcbbf
Reviewed-on: https://chromium-review.googlesource.com/c/breakpad/breakpad/+/2262932
Reviewed-by: Sterling Augustine <saugustine@google.com>
Reviewed-by: Mark Mentovai <mark@chromium.org>

src/processor/call_stack.cc

@@ -43,7 +43,7 @@ CallStack::~CallStack() {
 }
 
 void CallStack::Clear() {
-  for (vector<StackFrame *>::const_iterator iterator = frames_.begin();
+  for (vector<StackFrame*>::const_iterator iterator = frames_.begin();
        iterator != frames_.end();
        ++iterator) {
     delete *iterator;