Impact: minor new API
ksplice added a "starts_with" function, which seems like a common need.
When people open-code it they seem to use fixed numbers rather than strlen,
so it's quite a readability win (also, strncmp() almost always wants != 0
on it).
So here's strstarts().
Cc: Anders Kaseorg <andersk@mit.edu>
Cc: Jeff Arnold <jbarnold@mit.edu>
Cc: Tim Abbott <tabbott@mit.edu>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
66f92cf9d4