scripts/spelling.txt: fix incorrect typo-words

Fix up some incorrect typo-words.

[akpm@linux-foundation.org: "licencing" is valid British spelling and should be kept, per Joe]
Link: http://lkml.kernel.org/r/1486409689-23335-1-git-send-email-ross.zwisler@linux.intel.com
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>