scripts/spelling.txt: add typo "exprienced" and "rewritting"

Add typo "exprienced" and "rewritting".
They were found and fixed in follow patches:

Link: https://lore.kernel.org/all/[email protected]/
Link: https://lore.kernel.org/all/[email protected]/
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lore.kernel.org/all/[email protected]/
Signed-off-by: WangYuli <[email protected]>
Suggested-by: Simon Horman <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Cc: Colin Ian King <[email protected]>
Cc: Jesse Brandeburg <[email protected]>
Cc: WangYuli <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

Author: WangYuli

scripts/spelling.txt

@@ -674,6 +674,7 @@ explict||explicit
 explictely||explicitly
 explictly||explicitly
 expresion||expression
+exprienced||experienced
 exprimental||experimental
 extened||extended
 exteneded||extended
@@ -1388,6 +1389,7 @@ reuest||request
 reuqest||request
 reutnred||returned
 revsion||revision
+rewritting||rewriting
 rmeoved||removed
 rmeove||remove
 rmeoves||removes