swapping01: make use of tst_available_mem

Signed-off-by: Li Wang <liwang@redhat.com>
Reviewed-by: Cyril Hrubis <chrubis@suse.cz>
Reviewed-by: Petr Vorel <pvorel@suse.cz>

Author: wangli5665

testcases/kernel/mem/include/mem.h

@@ -4,6 +4,7 @@
 #include "tst_test.h"
 #include "tst_cgroup.h"
 #include "ksm_helper.h"
+#include "tst_memutils.h"
 
 #if defined(__powerpc__) || defined(__powerpc64__)
 #define MAXNODES		256

testcases/kernel/mem/swapping/swapping01.c

@@ -83,11 +83,7 @@ static void test_swapping(void)
 static void init_meminfo(void)
 {
 	swap_free_init = SAFE_READ_MEMINFO("SwapFree:");
-	if (FILE_LINES_SCANF("/proc/meminfo", "MemAvailable: %ld",
-		&mem_available_init)) {
-		mem_available_init = SAFE_READ_MEMINFO("MemFree:")
-			+ SAFE_READ_MEMINFO("Cached:");
-	}
+	mem_available_init = tst_available_mem();
 	mem_over = mem_available_init * COE_SLIGHT_OVER;
 	mem_over_max = mem_available_init * COE_DELTA;