You can't specify more than one table name in update.

Do it in the following way

UPDATE line l
SET l.pin = 8351
WHERE l.line_id = ( SELECT line_id from line_esl le
WHERE le.line_id = l.line_id
AND le.mdn = '4042108351'
AND le.esn = '09900311161' )
and l.account_id = (SELECT a.account_id from account a , company_number_location cnl
WHERE a.account_id = l.account_id
AND a.number_loc = cnl.number_loc
and cnl.company_cd = 'REVASDATA')