BE: Simplify expected_type code

Summary: Use the `SpecBody` now stored in `FunctionBody` when working with type mismatches.

Reviewed By: robertoaloi

Differential Revision: D55022168

fbshipit-source-id: 514c2712fd58344675d2d65f28577fb1810fbf30

crates/ide/src/diagnostics/eqwalizer_assists/expected_type.rs

@@ -19,6 +19,7 @@ use elp_types_db::eqwalizer::StructuredDiagnostic;
 use hir::InFile;
 use hir::Literal;
 use hir::Semantic;
+use hir::SpecBody;
 use hir::TypeExpr;
 use text_edit::TextEdit;
 
@@ -69,10 +70,9 @@ fn add_spec_fix(
         },
     )?;
     let function_id = sema.find_enclosing_function(file_id, &token.value.parent()?)?;
-    let def_map = sema.def_map(file_id);
-    let function_def = def_map.get_by_function_id(&InFile::new(file_id, function_id))?;
-    let spec_id = InFile::new(file_id, function_def.spec.clone()?.spec_id);
-    let spec_body = sema.db.spec_body(spec_id);
+    let function = sema.db.function_body(InFile::new(file_id, function_id));
+    let spec_body: &SpecBody = function.spec_body()?;
+    let spec_id = InFile::new(file_id, spec_body.spec_id()?);
     // We are looking for a single spec signature with a single atom return type.
     match &spec_body.sigs[..] {
         [sig] => {