t/no-mmap-inval: Replace valloc() with t_posix_memalign()

Address the limitations of valloc(). This function, which is primarily
used for allocating page-aligned memory, is not only absent in some
systems but is also marked as obsolete according to the `man 3 valloc`.

Replace valloc() with t_posix_memalign() to fix the following build
error:

  no-mmap-inval.c:28:56: warning: call to undeclared function 'valloc'; ISO C99 and \
  later do not support implicit function declarations [-Wimplicit-function-declaration]
          p.cq_off.user_addr = (unsigned long long) (uintptr_t) valloc(8192);
                                                                ^
  1 warning generated.

  ld.lld: error: undefined symbol: valloc
  >>> referenced by no-mmap-inval.c:28
  >>>               /tmp/no-mmap-inval-ea16a2.o:(main)
  >>> did you mean: calloc
  >>> defined in: /system/lib64/libc.so
  clang-15: error: linker command failed with exit code 1 (use -v to see invocation)
  make[1]: *** [Makefile:239: no-mmap-inval.t] Error 1

Signed-off-by: Ammar Faizi <[email protected]>
Reviewed-by: Alviro Iskandar Setiawan <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

test/no-mmap-inval.c

@@ -20,12 +20,14 @@ int main(int argc, char *argv[])
 		.flags		= IORING_SETUP_NO_MMAP,
 	};
 	struct io_uring ring;
+	void *addr;
 	int ret;
 
 	if (argc > 1)
 		return T_EXIT_SKIP;
 
-	p.cq_off.user_addr = (unsigned long long) (uintptr_t) valloc(8192);
+	t_posix_memalign(&addr, sysconf(_SC_PAGESIZE), 8192);
+	p.cq_off.user_addr = (unsigned long long) (uintptr_t) addr;
 
 	ret = io_uring_queue_init_params(2, &ring, &p);
 	if (ret == -EINVAL) {