Remove stray newline in tracing.zip filename

The uploaded trace is currently inaccessible because of the stray
newline.

BUG=455782
TEST=upload a feedback report with trace & download tracing.zip

Review URL: https://codereview.chromium.org/869853004

Cr-Commit-Position: refs/heads/master@{#314858}

components/feedback/feedback_data.cc

@@ -20,7 +20,7 @@ using content::BrowserThread;
 namespace feedback {
 namespace {
 
-const char kTraceFilename[] = "tracing.zip\n";
+const char kTraceFilename[] = "tracing.zip";
 const char kPerformanceCategoryTag[] = "Performance";
 
 const base::FilePath::CharType kHistogramsFilename[] =