x86/intel_rdt: Get rid of anon union

gcc-4.4.3 fails to statically initialize members of a anon union.
See: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=10676

The storage saving is not really worth it and aside of that it will catch
usage of the cache member for bandwidth and vice versa easier.

Fixes: 05b93417 ("x86/intel_rdt/mba: Add primary support for Memory Bandwidth Allocation (MBA)")
Reported-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

arch/x86/include/asm/intel_rdt.h

@@ -167,10 +167,8 @@ struct rdt_resource {
 				 struct rdt_resource *r);
 	int			data_width;
 	struct list_head	domains;
-	union {
-		struct rdt_cache	cache;
-		struct rdt_membw	membw;
-	};
+	struct rdt_cache	cache;
+	struct rdt_membw	membw;
 	struct rftype		*info_files;
 	int			nr_info_files;
 	const char		*format_str;