Rename some variables

Co-authored-by: Copilot <copilot@github.com>

Author: owen-mc

go/ql/lib/semmle/go/frameworks/CryptoLibraries.qll

@@ -386,15 +386,15 @@ private module Crypto {
 
       StreamReader() {
         lookThroughPointerType(this.getType()).hasQualifiedName("crypto/cipher", "StreamReader") and
-        exists(DataFlow::Write w, DataFlow::Node base, Field f |
-          f.hasQualifiedName("crypto/cipher", "StreamReader", "S") and
-          w.writesField(base, f, encryptionFlowTarget) and
-          DataFlow::localFlow(base, this)
+        exists(DataFlow::Write wS, DataFlow::Node baseS, Field fS |
+          fS.hasQualifiedName("crypto/cipher", "StreamReader", "S") and
+          wS.writesField(baseS, fS, encryptionFlowTarget) and
+          DataFlow::localFlow(baseS, this)
         ) and
-        exists(DataFlow::Write w, DataFlow::Node base, Field f |
-          f.hasQualifiedName("crypto/cipher", "StreamReader", "R") and
-          w.writesField(base, f, inputNode) and
-          DataFlow::localFlow(base, this)
+        exists(DataFlow::Write wR, DataFlow::Node baseR, Field fR |
+          fR.hasQualifiedName("crypto/cipher", "StreamReader", "R") and
+          wR.writesField(baseR, fR, inputNode) and
+          DataFlow::localFlow(baseR, this)
         )
       }