lib/test_kasan.c: fix memory leak in kmalloc_oob_krealloc_more()

BugLink: https://bugs.launchpad.net/bugs/1864775

commit 3e21d9a5 upstream.

In case memory resources for _ptr2_ were allocated, release them before
return.

Notice that in case _ptr1_ happens to be NULL, krealloc() behaves
exactly like kmalloc().

Addresses-Coverity-ID: 1490594 ("Resource leak")
Link: http://lkml.kernel.org/r/20200123160115.GA4202@embeddedor
Fixes: 3f15801c ("lib: add kasan test module")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

lib/test_kasan.c

@@ -93,6 +93,7 @@ static noinline void __init kmalloc_oob_krealloc_more(void)
 	if (!ptr1 || !ptr2) {
 		pr_err("Allocation failed\n");
 		kfree(ptr1);
+		kfree(ptr2);
 		return;
 	}