BUG #13101. STL ascii reader was report failures prematurely.

STL ascii reader was reporting error when eof was reached at an expected
location. This was causing the reader to fail for the STL file attached with the
bug report.

Change-Id: I734d2c8d8c85854df3d2a63bae6ba23bccf7a9c2

IO/vtkSTLReader.cxx

@@ -442,12 +442,15 @@ int vtkSTLReader::ReadASCIISTL(FILE *fp, vtkPoints *newPts,
         {
         if (!fgets(line, 255, fp))
           {
-          vtkErrorMacro ("STLReader error reading file: " << this->FileName
-                         << " Premature EOF while reading end solid.");
-          fclose(fp);
-          return 0;
+          done = feof(fp);
+          if (!done)
+            {
+            vtkErrorMacro ("STLReader error reading file: " << this->FileName
+              << " Premature EOF while reading end solid.");
+            fclose(fp);
+            return 0;
+            }
           }
-
         done = feof(fp);
         }