Disable clippy::map_identity

Summary:
See rust-lang/rust-clippy#11792

map_identity is causing build failures by taking its suggestion.

Once the fix is in, we can revert the changes to tools/buckconfigs/fbsource-common.bcfg in this diff.

Reviewed By: zertosh

Differential Revision: D53018763

fbshipit-source-id: a393dd9888a1320c19fc10de4b4c1e5d9b15bd43

shed/sorted_vector_map/src/map.rs

@@ -362,15 +362,11 @@ where
 
     /// Returns the first key-value pair in the map.
     pub fn first_key_value(&self) -> Option<(&K, &V)> {
-        // Fixed by https://github.com/rust-lang/rust-clippy/pull/11792
-        #[allow(clippy::map_identity)]
         self.0.first().map(|(k, v)| (k, v))
     }
 
     /// Returns the last key-value pair in the map.
     pub fn last_key_value(&self) -> Option<(&K, &V)> {
-        // Fixed by https://github.com/rust-lang/rust-clippy/pull/11792
-        #[allow(clippy::map_identity)]
         self.0.last().map(|(k, v)| (k, v))
     }
 
@@ -541,8 +537,6 @@ impl<'a, K: 'a, V: 'a> Iterator for Iter<'a, K, V> {
 
     #[inline]
     fn next(&mut self) -> Option<Self::Item> {
-        // Fixed by https://github.com/rust-lang/rust-clippy/pull/11792
-        #[allow(clippy::map_identity)]
         self.0.next().map(|(k, v)| (k, v))
     }
 
@@ -561,8 +555,6 @@ impl<'a, K: 'a, V: 'a> ExactSizeIterator for Iter<'a, K, V> {
 impl<'a, K: 'a, V: 'a> DoubleEndedIterator for Iter<'a, K, V> {
     #[inline]
     fn next_back(&mut self) -> Option<Self::Item> {
-        // Fixed by https://github.com/rust-lang/rust-clippy/pull/11792
-        #[allow(clippy::map_identity)]
         self.0.next_back().map(|(k, v)| (k, v))
     }
 }