Remove undefined symbols from libvirt_private.syms

MinGW's ld gives an error when trying to export undefined symbols.

src/libvirt_private.syms

@@ -362,7 +362,6 @@ virFree;
 
 
 # network.h
-virSocketAddrInNetwork;
 virSocketAddrIsNetmask;
 virSocketCheckNetmask;
 virSocketFormatAddr;
@@ -435,8 +434,6 @@ pciDeviceListDel;
 pciDeviceFileIterate;
 pciDeviceListCount;
 pciDeviceListGet;
-pciDeviceListLock;
-pciDeviceListUnlock;
 pciDeviceListSteal;
 
 
@@ -505,7 +502,6 @@ virStoragePoolObjUnlock;
 
 # storage_encryption_conf.h
 virStorageEncryptionFree;
-virStorageEncryptionDropSecrets;
 virStorageEncryptionParseNode;
 virStorageEncryptionFormat;
 virStorageGenerateQcowPassphrase;

src/util/network.h

@@ -40,10 +40,6 @@ int virSocketSetPort(virSocketAddrPtr addr, int port);
 
 int virSocketGetPort(virSocketAddrPtr addr);
 
-int virSocketAddrInNetwork(virSocketAddrPtr addr1,
-                           virSocketAddrPtr addr2,
-                           virSocketAddrPtr netmask);
-
 int virSocketGetRange     (virSocketAddrPtr start,
                            virSocketAddrPtr end);