chore: fix some comments (#4004)

Signed-off-by: divdeploy <chenguangxue@outlook.com>

substrate/frame/glutton/src/benchmarking.rs

@@ -85,7 +85,7 @@ benchmarks! {
 
 	empty_on_idle {
 	}: {
-		// Enough weight do do nothing.
+		// Enough weight to do nothing.
 		Glutton::<T>::on_idle(System::<T>::block_number(), T::WeightInfo::empty_on_idle());
 	}
 

substrate/frame/nomination-pools/test-staking/src/lib.rs

@@ -413,7 +413,7 @@ fn pool_slash_e2e() {
 			]
 		);
 
-		// At this point, 20 are safe from slash, 30 are unlocking but vulnerable to slash, and and
+		// At this point, 20 are safe from slash, 30 are unlocking but vulnerable to slash, and
 		// another 30 are active and vulnerable to slash. Let's slash half of them.
 		pallet_staking::slashing::do_slash::<Runtime>(
 			&POOL1_BONDED,

substrate/frame/society/src/tests.rs

@@ -558,7 +558,7 @@ fn suspended_candidate_rejected_works() {
 		assert_eq!(Balances::reserved_balance(40), 0);
 		assert_eq!(Balances::free_balance(Society::account_id()), 9990);
 
-		// Founder manually bestows membership on 50 and and kicks 70.
+		// Founder manually bestows membership on 50 and kicks 70.
 		assert_ok!(Society::bestow_membership(Origin::signed(10), 50));
 		assert_eq!(members(), vec![10, 20, 30, 40, 50]);
 		assert_eq!(candidates(), vec![60, 70]);