lib/test_printf: Switch to bitmap_zalloc()

Switch to bitmap_zalloc() to show clearly what we are allocating.
Besides that it returns pointer of bitmap type instead of opaque void *.

Link: http://lkml.kernel.org/r/20190304100009.65147-1-andriy.shevchenko@linux.intel.com
To: linux-kernel@vger.kernel.org
To: Andrew Morton <akpm@linux-foundation.org>
To: linux@rasmusvillemoes.dk
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>

lib/test_printf.c

@@ -481,14 +481,14 @@ static void __init
 large_bitmap(void)
 {
 	const int nbits = 1 << 16;
-	unsigned long *bits = kcalloc(BITS_TO_LONGS(nbits), sizeof(long), GFP_KERNEL);
+	unsigned long *bits = bitmap_zalloc(nbits, GFP_KERNEL);
 	if (!bits)
 		return;
 
 	bitmap_set(bits, 1, 20);
 	bitmap_set(bits, 60000, 15);
 	test("1-20,60000-60014", "%*pbl", nbits, bits);
-	kfree(bits);
+	bitmap_free(bits);
 }
 
 static void __init