revert temporary change

src/eigensolver/tridiag_solver/kernels.cpp

@@ -160,7 +160,7 @@ void calcEvecsFromWeightVec(const SizeType& k_row, const SizeType& k_col, const
       // Avoid NaN generated by deflated vectors.
       // It is a temporary workaround until deflated vectors are moved at the end of the local matrix.
       if (el_evec != 0)
-        el_evec = ws_el / el_evec;
+        el_evec = std::copysign(std::sqrt(std::abs(ws_el)), z_el) / el_evec;
     }
   }
 }