syscalls/{quotactl04, statx05}.c: Replace extra_opts[] with fs_opts[]

extra_opts[] is to store the options which are passed after device name
(e.g. fs-size: mkfs -t ext4 /dev/sda1 <fs-size>) so perfer to use
fs_opts[] for quotactl04.c and statx05.c.

Also add a hint to doc/test-writing-guidelines.txt.

References:
https://github.com/linux-test-project/ltp/blob/master/doc/test-writing-guidelines.txt
https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/syscalls/mmap/mmap16.c

Signed-off-by: Xiao Yang <[email protected]>
Acked-by: Yang Xu <[email protected]>

Author: yangx-jy

doc/test-writing-guidelines.txt

@@ -1116,6 +1116,9 @@ The extra options 'extra_opts' should either be 'NULL' if there are none, or a
 will be passed after device name. e.g: +mkfs -t ext4 -b 1024 /dev/sda1 102400+
 in this case.
 
+Note that perfer to store the options which can be passed before or after device
+name by 'fs_opts' array.
+
 2.2.17 Verifying a filesystem's free space
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 

testcases/kernel/syscalls/quotactl/quotactl04.c

@@ -102,10 +102,10 @@ static struct tcase {
 
 static void setup(void)
 {
-	const char *const extra_opts[] = {"-O quota,project", NULL};
+	const char *const fs_opts[] = {"-O quota,project", NULL};
 
 	test_id = geteuid();
-	SAFE_MKFS(tst_device->dev, tst_device->fs_type, NULL, extra_opts);
+	SAFE_MKFS(tst_device->dev, tst_device->fs_type, fs_opts, NULL);
 	SAFE_MOUNT(tst_device->dev, MNTPOINT, tst_device->fs_type, 0, "quota");
 	mount_flag = 1;
 }

testcases/kernel/syscalls/statx/statx05.c

@@ -87,12 +87,12 @@ static void run(unsigned int i)
 static void setup(void)
 {
 	char opt_bsize[32];
-	const char *const extra_opts[] = {"-O encrypt", opt_bsize, NULL};
+	const char *const fs_opts[] = {"-O encrypt", opt_bsize, NULL};
 	int ret;
 
 	snprintf(opt_bsize, sizeof(opt_bsize), "-b %i", getpagesize());
 
-	SAFE_MKFS(tst_device->dev, tst_device->fs_type, NULL, extra_opts);
+	SAFE_MKFS(tst_device->dev, tst_device->fs_type, fs_opts, NULL);
 	SAFE_MOUNT(tst_device->dev, MNTPOINT, tst_device->fs_type, 0, 0);
 	mount_flag = 1;