[master] Fixing doxygen warnings after merge of #5016.

Trivial changes.

src/lib/dhcp/libdhcp++.h

@@ -55,7 +55,7 @@ public:
     ///
     /// @return Pointer to the option definition or NULL pointer if option
     /// definition has not been found.
-    static OptionDefinitionPtr getOptionDef(const std::string& option_space,
+    static OptionDefinitionPtr getOptionDef(const std::string& space,
                                             const std::string& name);
 
     /// @brief Returns vendor option definition for a given vendor-id and code

src/lib/dhcp/option6_pdexclude.h

@@ -80,7 +80,7 @@ public:
 
     /// @brief Returns Prefix Exclude option in textual format.
     ///
-    /// @param ident Number of spaces to be inserted before the text.
+    /// @param indent Number of spaces to be inserted before the text.
     virtual std::string toText(int indent = 0) const;
 
     /// @brief Returns excluded prefix.

src/lib/dhcp/option_data_types.h

@@ -536,7 +536,7 @@ public:
     ///
     /// @param prefix_len Prefix length in bits (0 to 128).
     /// @param prefix Prefix value.
-    /// @param [out] Output buffer.
+    /// @param [out] buf Output buffer.
     static void writePrefix(const PrefixLen& prefix_len,
                             const asiolink::IOAddress& prefix,
                             std::vector<uint8_t>& buf);

src/lib/dhcpsrv/pool.h

@@ -226,7 +226,7 @@ public:
     /// option to a client.
     ///
     /// @param prefix specified a prefix of the pool.
-    /// @param prefix_Leb specifies prefix length of the pool.
+    /// @param prefix_len specifies prefix length of the pool.
     /// @param delegated_len specifies length of the delegated prefixes.
     /// @param excluded_prefix specifies an excluded prefix as per RFC6603.
     /// @param excluded_prefix_len specifies length of an excluded prefix.