dumpstate: Improve error message for failed dumps.

Format the header / footer in the same way as successful dumps
and include the PID in the failure message.

Test: Manual
Bug: 118090541
Change-Id: I17f51c816f4d3ebda4cd157b8d05be64008fb81e
diff --git a/cmds/dumpstate/utils.cpp b/cmds/dumpstate/utils.cpp
index d97ffbf..990fd43 100644
--- a/cmds/dumpstate/utils.cpp
+++ b/cmds/dumpstate/utils.cpp
@@ -871,7 +871,11 @@
             is_java_process ? 5 : 20, fd);
 
         if (ret == -1) {
-            dprintf(fd, "dumping failed, likely due to a timeout\n");
+            // For consistency, the header and footer to this message match those
+            // dumped by debuggerd in the success case.
+            dprintf(fd, "\n---- pid %d at [unknown] ----\n", pid);
+            dprintf(fd, "Dump failed, likely due to a timeout.\n");
+            dprintf(fd, "---- end %d ----", pid);
             timeout_failures++;
             continue;
         }