[MIPS] Replace __attribute_used__ with __used

Replaces the deprecated __attribute_used__ with __used.  Also makes some
style adjustments to abide by the kernel coding conventions.

Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/mm/c-sb1.c b/arch/mips/mm/c-sb1.c
index 6f9bd7f..85ce284 100644
--- a/arch/mips/mm/c-sb1.c
+++ b/arch/mips/mm/c-sb1.c
@@ -272,7 +272,7 @@
 /*
  * Invalidate all caches on this CPU
  */
-static void __attribute_used__ local_sb1___flush_cache_all(void)
+static void __used local_sb1___flush_cache_all(void)
 {
 	__sb1_writeback_inv_dcache_all();
 	__sb1_flush_icache_all();