scripts/spelling.txt: add some typo-words

I wrote a small script to show word-pair from all linux spelling-typo
commits, and get following result by sort | uniq -c:

    181 occured -> occurred
     78 transfered -> transferred
     67 recieved -> received
     65 dependant -> dependent
     58 wether -> whether
     56 accomodate -> accommodate
     54 occured -> occurred
     51 recieve -> receive
     47 cant -> can't
     40 sucessfully -> successfully
     ...

Some of them are not in spelling.txt, this patch adds the most common
word-pairs into spelling.txt.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>