Lift out an if statement

Summary: Suggestion from clippy. Seems equally good either way.

Reviewed By: JakobDegen

Differential Revision: D47226536

fbshipit-source-id: 82a9eb2a85760668a545d1c7ad54c9716bb16b5d

Author: ndmitchell

starlark/src/eval/bc/compiler/stmt.rs

@@ -194,14 +194,12 @@ impl IrSpanned<StmtCompiled> {
             expr.write_bc_cb(bc, |slot, bc| {
                 bc.write_instr::<InstrReturnCheckType>(span, slot);
             });
+        } else if let Some(value) = expr.as_value() {
+            bc.write_instr::<InstrReturnConst>(span, value);
         } else {
-            if let Some(value) = expr.as_value() {
-                bc.write_instr::<InstrReturnConst>(span, value);
-            } else {
-                expr.write_bc_cb(bc, |slot, bc| {
-                    bc.write_instr::<InstrReturn>(span, slot);
-                });
-            }
+            expr.write_bc_cb(bc, |slot, bc| {
+                bc.write_instr::<InstrReturn>(span, slot);
+            });
         }
     }