revokeRole spec mismatch (#2872)

revokeRole emits {RoleRevoked} event if `account` has been revoked `role`

Greetings from ChainSecurity!

contracts/access/AccessControl.sol

@@ -150,7 +150,7 @@ abstract contract AccessControl is Context, IAccessControl, ERC165 {
      * purpose is to provide a mechanism for accounts to lose their privileges
      * if they are compromised (such as when a trusted device is misplaced).
      *
-     * If the calling account had been granted `role`, emits a {RoleRevoked}
+     * If the calling account had been revoked `role`, emits a {RoleRevoked}
      * event.
      *
      * Requirements: