contrib/mempattern: hide mm_malloc()

Experience proved that it can be confused with mm_alloc()
and it may not be trivial to find the mistake.

contrib/mempattern.c

@@ -24,7 +24,7 @@ static void mm_nofree(void *p)
 	/* nop */
 }
 
-void *mm_malloc(void *ctx, size_t n)
+static void *mm_malloc(void *ctx, size_t n)
 {
 	(void)ctx;
 	return malloc(n);

contrib/mempattern.h

@@ -55,9 +55,6 @@ void mm_ctx_mempool(knot_mm_t *mm, size_t chunk_size);
 
 /* API in addition to Knot's mempattern. */
 
-/*! \brief Simple malloc wrapper.  */
-void *mm_malloc(void *ctx, size_t n);
-
 /*! \brief Readability: avoid const-casts in code. */
 static inline void free_const(const void *what)
 {
@@ -71,12 +68,14 @@ void *mm_malloc_aligned(void *ctx, size_t n);
 static inline void mm_ctx_init_aligned(knot_mm_t *mm, size_t alignment)
 {
 	assert(__builtin_popcount(alignment) == 1);
+	mm_ctx_init(mm);
 	mm->ctx = (uint8_t *)NULL + alignment; /*< roundabout to satisfy linters */
 	/* posix_memalign() doesn't allow alignment < sizeof(void*),
 	 * and there's no point in using it for small values anyway,
 	 * as plain malloc() guarantees at least max_align_t. */
-	mm->alloc = alignment > sizeof(max_align_t) ? mm_malloc_aligned : mm_malloc;
-	mm->free = free;
+	if (alignment > sizeof(max_align_t)) {
+		mm->alloc = mm_malloc_aligned;
+	}
 }
 
 /*! \brief New memory pool context, allocated on itself. */

lib/generic/lru.c

@@ -119,7 +119,7 @@ KR_EXPORT struct lru * lru_create_impl(uint max_slots, uint val_alignment,
 			mm_ctx_init_aligned(&mm_array_default, alignof(struct lru));
 		mm_array = &mm_array_default;
 	}
-	assert(mm_array->alloc != mm_malloc && mm_array->alloc != (knot_mm_alloc_t)mp_alloc);
+	assert(mm_array->alloc && mm_array->alloc != (knot_mm_alloc_t)mp_alloc);
 
 	size_t size = offsetof(struct lru, groups[group_count]);
 	struct lru *lru = mm_alloc(mm_array, size);