Fix elided_named_lifetimes warning

[ChrisDenton]

New on nightly

warning: elided lifetime has a name
   --> src\symbolize\gimli\macho.rs:253:77
    |
253 |     pub(super) fn search_object_map<'b>(&'b mut self, addr: u64) -> Option<(&Context<'b>, u64)> {
    |                                     -- lifetime `'b` declared here          ^ this elided lifetime gets resolved as `'b`
    |
    = note: `#[warn(elided_named_lifetimes)]` on by default

[workingjubilee]

whee!