Remove the redundant code, also fix the misleading comment in the code (

#3)

After PR #2 the else condition code becomes redundant this PR fixes
this. Also the comment is misleading in my view hence fixed that also.

dummy.cpp

@@ -137,18 +137,15 @@ int main(int argc, char *const argv[]) {
         return EXIT_FAILURE;
     }
 
-    if (!options.useFixed) {
-        options.setInputFile();
+    if (::errorCount() > 0) {
+            return EXIT_FAILURE;
     }
 
     const IR::P4Program *program = nullptr;
     if (options.useFixed) {
         program = P4Dummy::parseDummyP4(options);
     } else {
         options.setInputFile();
-        if (::errorCount() > 0) {
-            return EXIT_FAILURE;
-        }
         program = P4::parseP4File(options);
     }