fix "logcat -c ; logcat -d" hang.

Change-Id: I1dc3633fc7228a6ff8ed0da4572f40055a28ceb2
diff --git a/logcat/logcat.cpp b/logcat/logcat.cpp
index ae56c41..b71ce86 100644
--- a/logcat/logcat.cpp
+++ b/logcat/logcat.cpp
@@ -253,7 +253,7 @@
     int max = 0;
     int ret;
     int queued_lines = 0;
-    bool sleep = true;
+    bool sleep = false;
 
     int result;
     fd_set readset;