Print log when Pno scan started

In addition, We might need to keep using 'pno scan' instead of
'scheduled scan' in this class. This also fixes that.

Bug: None
Test: compile
Change-Id: I989d794583bb5474348c9679e5d444550710bf61
diff --git a/scanning/scanner_impl.cpp b/scanning/scanner_impl.cpp
index abf3d43..df0c722 100644
--- a/scanning/scanner_impl.cpp
+++ b/scanning/scanner_impl.cpp
@@ -248,9 +248,10 @@
                                        match_ssids,
                                        freqs)) {
     *out_success = false;
-    LOG(ERROR) << "Failed to start scheduled scan";
+    LOG(ERROR) << "Failed to start pno scan";
     return Status::ok();
   }
+  LOG(INFO) << "Pno scan started";
   pno_scan_started_ = true;
   *out_success = true;
   return Status::ok();