tools/testing: check correct variable in open_procmap()

Check if "procmap_out->fd" is negative instead of "procmap_out" (which is
a pointer).

Link: https://lkml.kernel.org/r/aDbFuUTlJTBqziVd@stanley.mountain
Fixes: bd23f29 ("tools/testing: add PROCMAP_QUERY helper functions in mm self tests")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: levi.yun <yeoreum.yun@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: Dan Carpenter

tools/testing/selftests/mm/vm_util.c

@@ -439,7 +439,7 @@ int open_procmap(pid_t pid, struct procmap_fd *procmap_out)
 	sprintf(path, "/proc/%d/maps", pid);
 	procmap_out->query.size = sizeof(procmap_out->query);
 	procmap_out->fd = open(path, O_RDONLY);
-	if (procmap_out < 0)
+	if (procmap_out->fd < 0)
 		ret = -errno;
 
 	return ret;