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

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

  swith||switch
  swithable||switchable
  swithed||switched
  swithing||switching

While we are here, fix the "update" to "updates" in the touched hunk in
drivers/net/wireless/marvell/mwifiex/wmm.c.

Link: http://lkml.kernel.org/r/1481573103-11329-2-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/scripts/recordmcount.pl b/scripts/recordmcount.pl
index faac4b1..0b6002b 100755
--- a/scripts/recordmcount.pl
+++ b/scripts/recordmcount.pl
@@ -318,7 +318,7 @@
     # instruction or the addiu one. herein, we record the address of the
     # first one, and then we can replace this instruction by a branch
     # instruction to jump over the profiling function to filter the
-    # indicated functions, or swith back to the lui instruction to trace
+    # indicated functions, or switch back to the lui instruction to trace
     # them, which means dynamic tracing.
     #
     #       c:	3c030000 	lui	v1,0x0