[lldb][test] LogTest: Fix stack overflow

[Michael137]

Summary

The expected function name requires 18 bytes of storage.

Caught by the public ASAN buildbot

[JDevlieghere]

Thanks!

lldb/unittests/Utility/LogTest.cpp

TEST_F(LogChannelEnabledTest, log_options) {
   }
 
   {
     EXPECT_TRUE(EnableChannel(getLogHandler(),
                               LLDB_LOG_OPTION_PREPEND_FILE_FUNCTION, "chan", {},
                               Err));
     llvm::StringRef Msg = logAndTakeOutputf("Hello World");
     char File[12];
-    char Function[17];
+    char Function[18];
 
     sscanf(Msg.str().c_str(),
            "%[^:]:%s                                 Hello World", File,
            Function);
     EXPECT_STRCASEEQ("LogTest.cpp", File);
     EXPECT_STREQ("logAndTakeOutputf", Function);
   }