[2095] a few more editorial fixes to comments.

src/lib/datasrc/memory/rdata_encoder.h

@@ -182,7 +182,7 @@ public:
     ///
     /// \note This implementation does not support RDATA (or any subfield of
     /// it) whose size exceeds 65535 bytes (max uint16_t value).  Such RDATA
-    /// may not necessarily considered invalid in terms of protocol
+    /// may not necessarily be considered invalid in terms of protocol
     /// specification, but in practice it's mostly useless because the
     /// corresponding RR won't fit in any valid DNS message.
     ///
@@ -272,8 +272,8 @@ private:
     RdataEncoderImpl* impl_;
 };
 
-// We use the following quick-hack version of encoder and "foreach"
-// operator until we implement the complete versions.  The plan is to
+// We use the following quick-hack version of "foreach"
+// operators until we implement the complete versions.  The plan is to
 // update the test cases that use these functions with the complete
 // functions/classes, and then remove the entire namespace.
 namespace testing {

src/lib/datasrc/memory/tests/rdata_encoder_unittest.cc

@@ -322,7 +322,7 @@ RdataEncoderTest::addRdataMultiCommon(const vector<ConstRdataPtr>& rrsigs) {
 
 TEST_F(RdataEncoderTest, encodeLargeRdata) {
     // There should be no reason for a large RDATA to fail in encoding,
-    // but we check such a  case explicitly.
+    // but we check such a case explicitly.
 
     encoded_data_.resize(65535); // max unsigned 16-bit int
     isc::util::InputBuffer buffer(&encoded_data_[0], encoded_data_.size());