be consistent with the arguments passed to signal handlers

The :process keyword argument is used inconsistently for symbols
    denoting functions and function objects. Furthermore, it isn't
    needed and unused in our own code.

src/c/unixint.d

@@ -337,15 +337,11 @@ handle_signal_now(cl_object signal_code, cl_object process)
                  * be a function, a symbol denoting a function or
                  * a symbol denoting a condition.
                  */
-                if (cl_find_class(2, signal_code, ECL_NIL) != ECL_NIL)
+                if (cl_find_class(2, signal_code, ECL_NIL) != ECL_NIL) {
                         cl_cerror(2, str_ignore_signal, signal_code);
-#ifdef ECL_THREADS
-                else if (!Null(process))
-                        _ecl_funcall3(signal_code, @':process', process);
-#endif
-                else
-                        _ecl_funcall1(signal_code);
-                break;
+                        break;
+                }
+                /* fallthrough */
         case t_cfun:
         case t_cfunfixed:
         case t_cclosure:

src/lsp/top.lsp

@@ -513,7 +513,7 @@ Use special code 0 to cancel this operation.")
   (restart-case (simple-terminal-interrupt)
     (continue ())))
 
-(defun terminal-interrupt (&key process (correctablep t))
+(defun terminal-interrupt (&key (correctablep t))
   (declare (ignore correctablep))
   #+threads
   (mp:without-interrupts