CLEANUP: assorted typo fixes in the code and comments

This is 22nd iteration of typo fixes
diff --git a/src/cfgdiag.c b/src/cfgdiag.c
index a06ae0f..f8e4a9e 100644
--- a/src/cfgdiag.c
+++ b/src/cfgdiag.c
@@ -8,7 +8,7 @@
 #include <haproxy/proxy.h>
 #include <haproxy/server.h>
 
-/* Use this fonction to emit diagnostic.
+/* Use this function to emit diagnostic.
  * This can be used as a shortcut to set value pointed by <ret> to 1 at the
  * same time.
  */