library/VTY: fix CONFIG prompt matching in f_vty_wait_for_prompt()

Matching the CONFIG prompt using implicit '\w+(*)' pattern is
a bad idea, because it can actually match almost anything:

  - 'OsmoBlaBla(config)# ',
  - 'OsmoBlaBla(config) ',
  - 'OsmoBlaBla> ',
  - 'Mahlzeit'!

One problem is that the parentheses are interpreted as a matching
operator (which is used to group an expression), so they should
have been escaped by '\'. Another problem is that this pattern
is not complete, because '\# ' is missing. Let's fix this!

Change-Id: I8a0e3fcfb0c4e5854b7b1e39296052e679c63c73
Related: OS#3675
1 file changed