scripts/spelling.txt: add "disassocation" pattern and fix typo instances

Fix typos and add the following to the scripts/spelling.txt:

  disassocation||disassociation

Link: http://lkml.kernel.org/r/1481573103-11329-27-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/net/wireless/intel/ipw2x00/ipw2200.c b/drivers/net/wireless/intel/ipw2x00/ipw2200.c
index c09215d..5ef3c5c 100644
--- a/drivers/net/wireless/intel/ipw2x00/ipw2200.c
+++ b/drivers/net/wireless/intel/ipw2x00/ipw2200.c
@@ -3974,7 +3974,7 @@ static void ipw_send_disassociate(struct ipw_priv *priv, int quiet)
 		return;
 	}
 
-	IPW_DEBUG_ASSOC("Disassocation attempt from %pM "
+	IPW_DEBUG_ASSOC("Disassociation attempt from %pM "
 			"on channel %d.\n",
 			priv->assoc_request.bssid,
 			priv->assoc_request.channel);