trace_processor: don't print extra new line in print events

If print event has a new line, strip it before printing to prevent
double new lines.

Bug: 126448611
Change-Id: I36dbcd692a157d9756caeeedc19667c98fa0872f
diff --git a/src/trace_processor/trace_processor_shell.cc b/src/trace_processor/trace_processor_shell.cc
index 7895af5..58cfff7 100644
--- a/src/trace_processor/trace_processor_shell.cc
+++ b/src/trace_processor/trace_processor_shell.cc
@@ -539,7 +539,7 @@
   }
 
   if (!RunQueryAndPrintResult(queries, stdout)) {
-    return false;
+    return 1;
   }
 
   // After this we can dump the database and exit if needed.