Fix clippy lint in cg_gcc

Author: GuillaumeGomez

compiler/rustc_codegen_gcc/src/builder.rs

@@ -503,8 +503,8 @@ fn set_rvalue_location<'a, 'gcc, 'tcx>(
     bx: &mut Builder<'a, 'gcc, 'tcx>,
     rvalue: RValue<'gcc>,
 ) -> RValue<'gcc> {
+    #[cfg(feature = "master")]
     if let Some(location) = bx.location {
-        #[cfg(feature = "master")]
         rvalue.set_location(location);
     }
     rvalue