log extra info for debugging

Make recovery log its PID, and when we use a block map file, log how
many ranges it contains.

Change-Id: I1b4299f8163af68a770b48c029ae25e6cb45d26b
diff --git a/recovery.cpp b/recovery.cpp
index 43cd9da..0a8c3b5 100644
--- a/recovery.cpp
+++ b/recovery.cpp
@@ -938,7 +938,7 @@
         return 0;
     }
 
-    printf("Starting recovery on %s", ctime(&start));
+    printf("Starting recovery (pid %d) on %s", getpid(), ctime(&start));
 
     load_volume_table();
     ensure_path_mounted(LAST_LOG_FILE);