On vacation, Ronnie Barker's to make comeback (5)
I believe the answer is:
recur
'make comeback' is the definition.
'on vacation ronnie barker's' is the wordplay.
'on vacation' says to hollow out the word (remove centre letters).
'barker' becomes 'cur' (cur can mean a dog, something which barks).
'ronnie' with its middle taken out is 're'.
're'+'cur'='RECUR'
'to' is the link.
(Other definitions for recur that I've seen before include "Happen again (5)" , "Repeat" , "Persist" , "Perseverate" , "Happen again or repetitively" .)