Consolidate the wait in recovery's reboot

After a reboot function call, we should always wait for it to finish
without executing other instructions.

Bug: 151110322
Test: build
Change-Id: I1dda291a0835ff96df7eaf42eba1a38267a3beeb
(cherry picked from commit 00c4aba9bf428717fc00e26a03e97401eca76ee8)
diff --git a/recovery.cpp b/recovery.cpp
index 0382697..7675121 100644
--- a/recovery.cpp
+++ b/recovery.cpp
@@ -781,13 +781,7 @@
           ui->Print("Retry attempt %d\n", retry_count);
 
           // Reboot back into recovery to retry the update.
-          if (!Reboot("recovery")) {
-            ui->Print("Reboot failed\n");
-          } else {
-            while (true) {
-              pause();
-            }
-          }
+          Reboot("recovery");
         }
         // If this is an eng or userdebug build, then automatically
         // turn the text display on if the script fails so the error