selftests/resctrl: Replace obsolete memalign() with posix_memalign()

memalign() is obsolete according to its manpage.

Replace memalign() with posix_memalign() and remove malloc.h include
that was there for memalign().

As a pointer is passed into posix_memalign(), initialize *p to NULL
to silence a warning about the function's return value being used as
uninitialized (which is not valid anyway because the error is properly
checked before p is returned).
Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

tools/testing/selftests/resctrl/fill_buf.c

@@ -14,7 +14,6 @@
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <inttypes.h>
-#include <malloc.h>
 #include <string.h>
 
 #include "resctrl.h"
@@ -64,11 +63,13 @@ static void mem_flush(void *p, size_t s)
 
 static void *malloc_and_init_memory(size_t s)
 {
+	void *p = NULL;
 	uint64_t *p64;
 	size_t s64;
+	int ret;
 
-	void *p = memalign(PAGE_SIZE, s);
-	if (!p)
+	ret = posix_memalign(&p, PAGE_SIZE, s);
+	if (ret < 0)
 		return NULL;
 
 	p64 = (uint64_t *)p;