Remove extraneous comma in printf vargs

Bug: skia:
Change-Id: I5e40d9c334c959e1a777251e1ac25f3703f9b7f9
Reviewed-on: https://skia-review.googlesource.com/c/159327
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
diff --git a/tests/ProcessorTest.cpp b/tests/ProcessorTest.cpp
index 6107b50..5594b0a 100644
--- a/tests/ProcessorTest.cpp
+++ b/tests/ProcessorTest.cpp
@@ -493,7 +493,7 @@
             // Finished analyzing the entire image, see if the number of pixel failures meets the
             // threshold for an FP violating the optimization requirements.
             if (failedPixelCount > kMaxAcceptableFailedPixels) {
-                ERRORF(reporter, "Processor violated %d of %d pixels, seed: 0x%08x, processor: %s",
+                ERRORF(reporter, "Processor violated %d of %d pixels, seed: 0x%08x, processor: %s"
                        ", first failing pixel details are below:",
                        failedPixelCount, kRenderSize * kRenderSize, seed,
                        clone->dumpInfo().c_str());