Rename C function `mrb_proc_lambda`.

mrbgems/mruby-proc-ext/src/proc.c

@@ -6,7 +6,7 @@
 #include <mruby/debug.h>
 
 static mrb_value
-mrb_proc_lambda(mrb_state *mrb, mrb_value self)
+mrb_proc_lambda_p(mrb_state *mrb, mrb_value self)
 {
   struct RProc *p = mrb_proc_ptr(self);
   return mrb_bool_value(MRB_PROC_STRICT_P(p));
@@ -169,7 +169,7 @@ void
 mrb_mruby_proc_ext_gem_init(mrb_state* mrb)
 {
   struct RClass *p = mrb->proc_class;
-  mrb_define_method(mrb, p, "lambda?",         mrb_proc_lambda,          MRB_ARGS_NONE());
+  mrb_define_method(mrb, p, "lambda?",         mrb_proc_lambda_p,        MRB_ARGS_NONE());
   mrb_define_method(mrb, p, "source_location", mrb_proc_source_location, MRB_ARGS_NONE());
   mrb_define_method(mrb, p, "to_s",            mrb_proc_inspect,         MRB_ARGS_NONE());
   mrb_define_method(mrb, p, "inspect",         mrb_proc_inspect,         MRB_ARGS_NONE());