Remove newline from "capturing trace..."

Turns out this broke a test.

Bug: 37906221
Test: Compiled
Change-Id: I750a2831114071de2627da08de033cbe7924b51b
diff --git a/cmds/atrace/atrace.cpp b/cmds/atrace/atrace.cpp
index 84820a6..ed53af1 100644
--- a/cmds/atrace/atrace.cpp
+++ b/cmds/atrace/atrace.cpp
@@ -1234,7 +1234,7 @@
 
     if (ok && traceStart) {
         if (!traceStream) {
-            printf("capturing trace...\n");
+            printf("capturing trace...");
             fflush(stdout);
         }