rust: bug: Support DEBUG_BUGVERBOSE_DETAILED option

rust: bug: Support DEBUG_BUGVERBOSE_DETAILED option

Make warn_on() support DEBUG_BUGVERBOSE_DETAILED option, which was
introduced by the commit aec58b48517c ("bugs/core: Extend
__WARN_FLAGS() with the 'cond_str' parameter").

When the option is enabled, WARN splats now show the evaluated
warn_on() condition alongside the file path, e.g.:

------------[ cut here ]------------
WARNING: [val == 1] linux/samples/rust/rust_minimal.rs:27 at _RNvXCsk7t4azzUqHP_12rust_minimalNtB2_11RustMinimalNtCs8pcx3n4
Modules linked in: rust_minimal(+)

Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260108013350.2880613-1-fujita.tomonori@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>