Removed compile warnings about files that could not be removed.

src/exe/co_convert/src/cnv_readwbl.cpp

@@ -1224,7 +1224,7 @@ int CnvReadWbl::copy_tmp_file(const char* tmpfilename, std::ofstream& fp_to)
     fp_to.put(c);
   fclose(fp);
 
-  sprintf(cmd, "rm %s &> /dev/null", tmpfilename);
+  sprintf(cmd, "rm -f %s", tmpfilename);
   system(cmd);
 
   return 1;

src/exe/co_convert/src/cnv_topdf.cpp

@@ -306,7 +306,7 @@ int CnvPdfObj::print_image()
 
   cnv_free_image(image, pixmap);
   fimg.close();
-  sprintf(cmd, "rm %s &> /dev/null", fname);
+  sprintf(cmd, "rm -f %s", fname);
   system(cmd);
   return 1;
 }