Fix typos.

llvm-svn: 212553
diff --git a/lldb/tools/debugserver/source/DNB.h b/lldb/tools/debugserver/source/DNB.h
index 6b9268c..177c4bd 100644
--- a/lldb/tools/debugserver/source/DNB.h
+++ b/lldb/tools/debugserver/source/DNB.h
@@ -39,7 +39,7 @@
 nub_process_t   DNBProcessLaunch        (const char *path, 
                                          char const *argv[], 
                                          const char *envp[], 
-                                         const char *working_directory, // NULL => dont' change, non-NULL => set working directory for inferior to this
+                                         const char *working_directory, // NULL => don't change, non-NULL => set working directory for inferior to this
                                          const char *stdin_path,
                                          const char *stdout_path,
                                          const char *stderr_path,