Swift: Fix QL-for-QL warnings.

Author: geoffw0

swift/ql/lib/codeql/swift/frameworks/StandardLibrary/Collection.qll

@@ -47,8 +47,6 @@ private class CollectionFieldsInheritTaint extends TaintInheritingContent,
   DataFlow::Content::FieldContent
 {
   CollectionFieldsInheritTaint() {
-    this.getField()
-        .(FieldDecl)
-        .hasQualifiedName(["Collection", "BidirectionalCollection"], ["first", "last"])
+    this.getField().hasQualifiedName(["Collection", "BidirectionalCollection"], ["first", "last"])
   }
 }

swift/ql/lib/codeql/swift/frameworks/StandardLibrary/NsString.qll

@@ -133,7 +133,6 @@ private class NsStringFieldsInheritTaint extends TaintInheritingContent,
 {
   NsStringFieldsInheritTaint() {
     this.getField()
-        .(FieldDecl)
         .hasQualifiedName("NSString",
           [
             "utf8String", "lowercased", "localizedLowedCase", "uppercased", "localizedUppercase",

swift/ql/lib/codeql/swift/frameworks/StandardLibrary/Sequence.qll

@@ -36,5 +36,5 @@ private class SequenceSummaries extends SummaryModelCsv {
 private class SequenceFieldsInheritTaint extends TaintInheritingContent,
   DataFlow::Content::FieldContent
 {
-  SequenceFieldsInheritTaint() { this.getField().(FieldDecl).hasQualifiedName("Sequence", "lazy") }
+  SequenceFieldsInheritTaint() { this.getField().hasQualifiedName("Sequence", "lazy") }
 }

swift/ql/lib/codeql/swift/frameworks/StandardLibrary/String.qll

@@ -125,7 +125,6 @@ private class StringFieldsInheritTaint extends TaintInheritingContent,
 {
   StringFieldsInheritTaint() {
     this.getField()
-        .(FieldDecl)
         .hasQualifiedName(["String", "StringProtocol"],
           [
             "unicodeScalars", "utf8", "utf16", "lazy", "utf8CString", "description",