hw/i386/x86: Eliminate two if statements in x86_bios_rom_init()

Given that memory_region_set_readonly() is a no-op when the readonlyness is
already as requested it is possible to simplify the pattern

  if (condition) {
    foo(true);
  }

to

  foo(condition);

which is shorter and allows to see the invariant of the code more easily.

Signed-off-by: Bernhard Beschow <shentey@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20240430150643.111976-2-shentey@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
diff --git a/hw/i386/x86.c b/hw/i386/x86.c
index 3d5b51e..2a4f3ee 100644
--- a/hw/i386/x86.c
+++ b/hw/i386/x86.c
@@ -1163,9 +1163,7 @@
         load_image_size(filename, ptr, bios_size);
         x86_firmware_configure(ptr, bios_size);
     } else {
-        if (!isapc_ram_fw) {
-            memory_region_set_readonly(bios, true);
-        }
+        memory_region_set_readonly(bios, !isapc_ram_fw);
         ret = rom_add_file_fixed(bios_name, (uint32_t)(-bios_size), -1);
         if (ret != 0) {
             goto bios_error;
@@ -1182,9 +1180,7 @@
                                         0x100000 - isa_bios_size,
                                         isa_bios,
                                         1);
-    if (!isapc_ram_fw) {
-        memory_region_set_readonly(isa_bios, true);
-    }
+    memory_region_set_readonly(isa_bios, !isapc_ram_fw);
 
     /* map all the bios at the top of memory */
     memory_region_add_subregion(rom_memory,