wifi_drv: implement vzalloc

This function is called by the rarely executed error handling code
(iwl_mvm_fw_error_dump) of wifi.lib.so.

repos/dde_linux/src/lib/wifi/dummies.cc

@@ -346,7 +346,6 @@ DUMMY(-1, ktime_sub)
 DUMMY(-1, sg_init_one)
 DUMMY(-1, vlan_hw_offload_capable)
 DUMMY(-1, vlan_tx_tag_get_id)
-DUMMY(-1, vzalloc)
 DUMMY(-1, tsk_restore_flags)
 DUMMY(-1, put_user)
 

repos/dde_linux/src/lib/wifi/lxcc_emul.cc

@@ -407,6 +407,17 @@ void *vmalloc(unsigned long size)
 }
 
 
+void *vzalloc(unsigned long size)
+{
+	void *addr = vmalloc(size);
+
+	if (addr)
+		memset(addr, 0, size);
+
+	return addr;
+}
+
+
 void vfree(const void *addr)
 {
 	if (!addr) return;