[rtl/controller] Remove redundant check in execption handling

This commit turns the last case in the exception handling if/else block
from an `else if` to an `else`. This is not changing functional
behavior as the same condition is checked previously, but removes a
`MISSING_ELSE` coverage hole reported by @udinator.

Signed-off-by: Pirmin Vogel <vogelpi@lowrisc.org>

rtl/ibex_controller.sv

@@ -540,7 +540,7 @@ module ibex_controller (
             exc_cause_o = EXC_CAUSE_STORE_ACCESS_FAULT;
             csr_mtval_o = lsu_addr_last_i;
 
-          end else if (load_err_q) begin
+          end else begin // load_err_q
             exc_cause_o = EXC_CAUSE_LOAD_ACCESS_FAULT;
             csr_mtval_o = lsu_addr_last_i;
           end