Update scopeguard.rs

I accidentally discovered that some minor changes in a production project will cause a lot of size increase and some performance regression. After comparison, I found a lot of `ScopeGuard::drop` symbols appeared in the poorer version.

I suspect this is because the compiler missed some inline. for `ScopeGuard`, it should always be beneficial to inline it.

Author: quininer

src/scopeguard.rs

@@ -42,7 +42,7 @@ impl<T, F> Drop for ScopeGuard<T, F>
 where
     F: FnMut(&mut T),
 {
-    #[cfg_attr(feature = "inline-more", inline)]
+    #[inline]
     fn drop(&mut self) {
         (self.dropfn)(&mut self.value)
     }