Update berryphase.cpp (#3876)

* Update berryphase.cpp

Initialize ik_1 and ik_2 in berryphase.cpp

* Update berryphase.cpp

Initialize modulus in berryphase.cpp

source/module_io/berryphase.cpp

@@ -239,8 +239,8 @@ double berryphase::stringPhase(int index_str,
 {
 	std::complex<double> zeta(1.0, 0.0);
 	ModuleBase::ComplexMatrix mat(nbands,nbands);
-	int ik_1;
-	int ik_2;
+	int ik_1 = 0;
+	int ik_2 = 0;
 	ModuleBase::Vector3<double> G(0.0,0.0,0.0);
 	ModuleBase::Vector3<double> dk = kv.kvec_c[ k_index[index_str][1] ] - kv.kvec_c[ k_index[index_str][0] ];
 	//GlobalV::ofs_running << "the std::string index is " << index_str << std::endl;
@@ -577,7 +577,7 @@ void berryphase::Macroscopic_polarization(const int npwx,
 	// ion polarization	end
 
 	// calculate Macroscopic polarization modulus because berry phase
-	int modulus;
+	int modulus = 0;
 	if( (!lodd) && (GlobalV::NSPIN==1) ) modulus = 2;
 	else modulus = 1;