Fixed usage info for SampleApp's msaa flag

http://codereview.appspot.com/6159043/

committed on behalf of Guanqun Lu



git-svn-id: http://skia.googlecode.com/svn/trunk@3817 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/samplecode/SampleApp.cpp b/samplecode/SampleApp.cpp
index 9bcd1f0..213a39f 100644
--- a/samplecode/SampleApp.cpp
+++ b/samplecode/SampleApp.cpp
@@ -654,7 +654,7 @@
 }
 
 static void usage(const char * argv0) {
-    SkDebugf("%s [--slide sampleName] [-i resourcePath] [-msaa sampleCount]\n", argv0);
+    SkDebugf("%s [--slide sampleName] [-i resourcePath] [--msaa sampleCount]\n", argv0);
     SkDebugf("    sampleName: sample at which to start.\n");
     SkDebugf("    resourcePath: directory that stores image resources.\n");
     SkDebugf("    msaa: request multisampling with the given sample count.\n");