fix(kldunload): remove unused -X option

The option `-X arg` for `compgen` is specified twice, but only the
latter takes effect.  Also, `-X kernel` excludes the word `kernel` but
the latter `-X '!*.ko'` also excludes the word `kernel` because it
only leaves the words matches the pattern `*.ko`.  Thus, we can just
filter the words by `-X '!*.ko'`.

completions/kldunload

@@ -7,7 +7,7 @@ _comp_cmd_kldunload()
     local cur prev words cword comp_args
     _comp_initialize -- "$@" || return
 
-    COMPREPLY=($(compgen -W '$(kldstat)' -X 'kernel' -X '!*.ko' -- "$cur"))
+    COMPREPLY=($(compgen -W '$(kldstat)' -X '!*.ko' -- "$cur"))
     COMPREPLY=(${COMPREPLY[@]%.ko})
 } &&
     complete -F _comp_cmd_kldunload kldunload