remove duplicate declaration of pb_variable util function

Author: dtebbs

libsnark/gadgetlib1/pb_variable.hpp

@@ -94,17 +94,6 @@ class pb_variable_array : private std::vector<pb_variable<FieldT>>
     FieldT get_field_element_from_bits(const protoboard<FieldT> &pb) const;
 };
 
-/// A utility function which creates and allocates a variable in a single step
-/// (and can therefore be used in initalizer lists, which greatly simplifies
-/// many constructors).
-///
-/// TODO: Why does pb_variable not have an allocating constructor of this form,
-/// even further simplifying a lot of code. Move this to an appropriate
-/// constructor if there are no issues.
-template<typename FieldT>
-pb_variable<FieldT> pb_variable_allocate(
-    protoboard<FieldT> &pb, const std::string &annotation);
-
 /* index 0 corresponds to the constant term (used in legacy code) */
 #define ONE pb_variable<FieldT>(0)