Fix formatting: remove trailing spaces, #endif with comments (> 10 lines)
diff --git a/library/memory_buffer_alloc.c b/library/memory_buffer_alloc.c
index 5176176..5409a93 100644
--- a/library/memory_buffer_alloc.c
+++ b/library/memory_buffer_alloc.c
@@ -539,7 +539,7 @@
     buffer_alloc_free( ptr );
     polarssl_mutex_unlock( &heap.mutex );
 }
-#endif
+#endif /* POLARSSL_THREADING_C */
 
 int memory_buffer_alloc_init( unsigned char *buf, size_t len )
 {