adb: bail out if wait_for_device fails in send_shell_command.

Bug: http://b/27166186
Change-Id: Ib7e9d7e6b909d67a3af94c3517a6a0b54cf17db7
(cherry picked from commit f56c39194f1c2a4f0ea5d2ac20aebf80de4b0ae7)
diff --git a/adb/commandline.cpp b/adb/commandline.cpp
index 8e76168..37d1146 100644
--- a/adb/commandline.cpp
+++ b/adb/commandline.cpp
@@ -1106,8 +1106,9 @@
         }
 
         fprintf(stderr,"- waiting for device -\n");
-        adb_sleep_ms(1000);
-        wait_for_device("wait-for-device", transport_type, serial);
+        if (!wait_for_device("wait-for-device", transport_type, serial)) {
+            return 1;
+        }
     }
 
     int exit_code = read_and_dump(fd, use_shell_protocol);