Only print the Bazel command line once.

Test: USE_BAZEL=1 m and USE_BAZEL=1 use_rbe m.
Change-Id: I8413e92d91c906f884628bedac6955575cf86a1c
diff --git a/ui/build/bazel.go b/ui/build/bazel.go
index 1cab8f8..23b14ee 100644
--- a/ui/build/bazel.go
+++ b/ui/build/bazel.go
@@ -156,9 +156,6 @@
 		"//:"+config.TargetProduct()+"-"+config.TargetBuildVariant(),
 	)
 
-	// Print the full command line for debugging purposes.
-	ctx.Println(cmd.Cmd)
-
 	// Execute the command at the root of the directory.
 	cmd.Dir = filepath.Join(config.OutDir(), "..")