[gdb/testsuite] Add missing returns in gdb.threads/infcall-from-bp-cond-simple.c

While investigating PR32785 I noticed a missing return statement in
worker_func, and compiling with -Wreturn-type showed another in
function_that_segfaults:
...
$ gcc gdb/testsuite/gdb.threads/infcall-from-bp-cond-simple.c -Wreturn-type
infcall-from-bp-cond-simple.c: In function ‘function_that_segfaults’:
infcall-from-bp-cond-simple.c:46:1: warning: \
  control reaches end of non-void function [-Wreturn-type]
   46 | }
      | ^
infcall-from-bp-cond-simple.c: In function ‘worker_func’:
infcall-from-bp-cond-simple.c:58:1: warning: \
  control reaches end of non-void function [-Wreturn-type]
   58 | }
      | ^
...

Fix these by adding the missing returns.

0 files changed, 0 insertions, 0 deletions