[WIDL] Minor cleanups following wine-10.0 sync (#8461)

Addendum to commit 8608467b84 (PR #8305).

- Remove redundant `#ifndef __REACTOS__ ... #endif` inside such an
  already existing block.
  See https://github.com/reactos/reactos/pull/8305#discussion_r2510118529

- Move the `getenv("TEMP")` ReactOS-specific fix to a better place.

- Reduce diff with respect to what we had prior to the sync.
  See https://github.com/reactos/reactos/pull/8305#discussion_r2509976210

sdk/tools/tools.h

@@ -382,14 +382,6 @@ static inline char *make_temp_dir(void)
     char *name;
     const char *tmpdir = NULL;
 
-#ifdef __REACTOS__
-#ifdef _WIN32
-    if (!(tmpdir = getenv("TEMP"))) tmpdir = "temp";
-#else
-    if (!(tmpdir = getenv("TMPDIR"))) tmpdir = "/tmp";
-#endif
-#endif
-
     for (count = 0; count < 0x8000; count++)
     {
         if (tmpdir)
@@ -400,7 +392,11 @@ static inline char *make_temp_dir(void)
         value += 7777;
         if (errno == EACCES && !tmpdir)
         {
+#if defined(__REACTOS__) && defined(_WIN32)
+            if (!(tmpdir = getenv("TEMP"))) tmpdir = "temp";
+#else
             if (!(tmpdir = getenv("TMPDIR"))) tmpdir = "/tmp";
+#endif
         }
         free( name );
     }

sdk/tools/widl/parser.y

@@ -2157,7 +2157,7 @@ static type_t *reg_typedefs( struct location where, decl_spec_t *decl_spec, decl
         type->attrs = attrs;
   }
 
-#ifdef __REACTOS__  /* r53187 / 5bf224e */
+#ifdef __REACTOS__ /* r53187 / 5bf224e */
   /* Append the SWITCHTYPE attribute to a non-encapsulated union if it does not already have it.  */
   if (type_get_type_detect_alias(type) == TYPE_UNION &&
       is_attr(attrs, ATTR_SWITCHTYPE) &&

sdk/tools/widl/widl.c

@@ -686,13 +686,11 @@ int open_typelib( const char *name )
             TRYOPEN( strmake( "%s/wine%s/%s", libdir, pe_dir, name ));
             TRYOPEN( strmake( "%s/wine/%s", libdir, name ));
         }
-#ifndef __REACTOS__
         for (i = 0; i < ARRAY_SIZE(default_dirs); i++)
         {
             if (i && !strcmp( default_dirs[i], default_dirs[0] )) continue;
             TRYOPEN( strmake( "%s%s/%s", default_dirs[i], pe_dir, name ));
         }
-#endif
     }
 #endif