Apply suggestions from code review

Co-authored-by: Tom Hvitved <hvitved@github.com>

Author: aibaars

ruby/ql/lib/codeql/ruby/ast/Variable.qll

@@ -183,7 +183,7 @@ class InstanceVariableAccess extends VariableAccess instanceof InstanceVariableA
   final override string getAPrimaryQlClass() { result = "InstanceVariableAccess" }
 
   /**
-   * Gets the synthetic receiver(`self`) of this instance variable access.
+   * Gets the synthetic receiver (`self`) of this instance variable access.
    */
   final SelfVariableAccess getReceiver() { synthChild(this, 0, result) }
 

ruby/ql/lib/codeql/ruby/controlflow/CfgNodes.qll

@@ -626,7 +626,7 @@ module ExprNodes {
     override InstanceVariableAccess getExpr() { result = ExprCfgNode.super.getExpr() }
 
     /**
-     * Gets the synthetic receiver(`self`) of this instance variable access.
+     * Gets the synthetic receiver (`self`) of this instance variable access.
      */
     final CfgNode getReceiver() { e.hasCfgChild(e.getReceiver(), this, result) }
   }