implemented pr fixes

Author: dilanbhalla

cpp/ql/src/experimental/Security/CWE/CWE-120/MemoryUnsafeFunctionScan.ql

@@ -15,9 +15,5 @@ import semmle.code.cpp.commons.Scanf
 from FunctionCall call, ScanfFunction sff
 where
   call.getTarget() = sff and
-  (
-    call.getArgument(sff.getFormatParameterIndex()).toString().regexpMatch(".*%s.*")
-    or
-    call.getArgument(sff.getFormatParameterIndex()).toString() = (".*%ls.*")
-  )
+  call.getArgument(sff.getFormatParameterIndex()).getValue().regexpMatch(".*%l?s.*")
 select call, "Dangerous use of one of the scanf functions"