Kernel+LibC: Remove ESUCCESS

There's no official ESUCCESS==0 errno code, and it keeps breaking the
Lagom build when we use it, so let's just say 0 instead.

Libraries/LibLine/Editor.cpp

@@ -654,7 +654,7 @@ Vector<size_t, 2> Editor::vt_dsr()
     do {
         auto nread = read(0, buf + length, 16 - length);
         if (nread < 0) {
-            if (errno == ESUCCESS) {
+            if (errno == 0) {
                 // ????
                 continue;
             }