tools/testing/selftests/vm: remove duplicate headers

Code cleanup: Remove duplicate headers which are included twice.
Signed-off-by: NJagadeesh Pagadala <jagdsh.linux@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Brian Geffon <bgeffon@google.com>
Link: http://lkml.kernel.org/r/1587278984-18847-1-git-send-email-jagdsh.linux@gmail.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

tools/testing/selftests/vm/mremap_dontunmap.c

@@ -11,7 +11,6 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <stdlib.h>
 #include <unistd.h>
 
 #include "../kselftest.h"