Code style: replace tabs with spaces
diff --git a/ndn-cpp/c/encoding/binary-xml-data.c b/ndn-cpp/c/encoding/binary-xml-data.c
index 385d229..776ca74 100644
--- a/ndn-cpp/c/encoding/binary-xml-data.c
+++ b/ndn-cpp/c/encoding/binary-xml-data.c
@@ -27,7 +27,7 @@
       (encoder, ndn_BinaryXml_DTag_SignatureBits, signature->signature, signature->signatureLength))
     return error;
   
-	if (error = ndn_BinaryXmlEncoder_writeElementClose(encoder))
+  if (error = ndn_BinaryXmlEncoder_writeElementClose(encoder))
     return error;
   
   return 0;    
@@ -90,7 +90,7 @@
   if (error = ndn_encodeBinaryXmlKeyLocator(&signedInfo->keyLocator, encoder))
     return error;
   
-	if (error = ndn_BinaryXmlEncoder_writeElementClose(encoder))
+  if (error = ndn_BinaryXmlEncoder_writeElementClose(encoder))
     return error;
   
   return 0;  
@@ -148,7 +148,7 @@
       (encoder, ndn_BinaryXml_DTag_Content, data->content, data->contentLength))
     return error;
   
-	if (error = ndn_BinaryXmlEncoder_writeElementClose(encoder))
+  if (error = ndn_BinaryXmlEncoder_writeElementClose(encoder))
     return error;
   
   return 0;