Simplify fetch1

Do the +4 in a single place. This shouldn't cause any difference
in behaviour as these are sequential variable assignments.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

fetch1.vhdl

@@ -49,19 +49,18 @@ begin
 
 	if stall_in = '0' then
 	    v.nia := r_int.nia_next;
-	    v_int.nia_next := std_logic_vector(unsigned(r_int.nia_next) + 4);
 	end if;
 
 	if e_in.redirect = '1' then
 	    v.nia := e_in.redirect_nia;
-	    v_int.nia_next := std_logic_vector(unsigned(e_in.redirect_nia) + 4);
 	end if;
 
 	if rst = '1' then
 	    v.nia := RESET_ADDRESS;
-	    v_int.nia_next := std_logic_vector(unsigned(RESET_ADDRESS) + 4);
 	end if;
 
+	v_int.nia_next := std_logic_vector(unsigned(v.nia) + 4);
+
 	-- Update registers
 	rin <= v;
 	rin_int <= v_int;