doc typo

Change-Id: I5dffd69a1bd983db5e23d0e72ed8cf6baba1b004
Reviewed-on: https://dart-review.googlesource.com/c/82886
Reviewed-by: Paul Berry <paulberry@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Phil Quitslund <pquitslund@google.com>

Author: pq

pkg/analyzer/lib/src/lint/linter.dart

@@ -391,7 +391,7 @@ abstract class NodeLintRuleWithContext extends NodeLintRule {
   /// in the given [registry].
   ///
   /// The node processors may use the provided [context] to access information
-  /// that is not avaiable from the AST nodes or their associated elements.
+  /// that is not available from the AST nodes or their associated elements.
   /// In a future release of the analyzer, [context] will become a required
   /// parameter.
   void registerNodeProcessors(NodeLintRegistry registry,