KVM: selftests: Fix spelling mistake "miliseconds" -> "milliseconds"

There is a spelling mistake in the help for the -p option. Fix it.
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20230417175322.53249-1-colin.i.king@gmail.comSigned-off-by: Sean Christopherson <seanjc@google.com>

tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.c

@@ -226,7 +226,7 @@ static void help(char *name)
 	puts("");
 	printf("usage: %s [-h] [-p period_ms] [-t token]\n", name);
 	puts("");
-	printf(" -p: The NX reclaim period in miliseconds.\n");
+	printf(" -p: The NX reclaim period in milliseconds.\n");
 	printf(" -t: The magic token to indicate environment setup is done.\n");
 	printf(" -r: The test has reboot permissions and can disable NX huge pages.\n");
 	puts("");