f2fs: rework fault injection handling to avoid a warning

When CONFIG_F2FS_FAULT_INJECTION is disabled, we get a warning about an
unused label:

fs/f2fs/segment.c: In function '__submit_discard_cmd':
fs/f2fs/segment.c:1059:1: error: label 'submit' defined but not used [-Werror=unused-label]

This could be fixed by adding another #ifdef around it, but the more
reliable way of doing this seems to be to remove the other #ifdefs
where that is easily possible.

By defining time_to_inject() as a trivial stub, most of the checks for
CONFIG_F2FS_FAULT_INJECTION can go away. This also leads to nicer
formatting of the code.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 472dd643..dd2e45a 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -2323,12 +2323,11 @@ bool f2fs_alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid)
 	struct f2fs_nm_info *nm_i = NM_I(sbi);
 	struct free_nid *i = NULL;
 retry:
-#ifdef CONFIG_F2FS_FAULT_INJECTION
 	if (time_to_inject(sbi, FAULT_ALLOC_NID)) {
 		f2fs_show_injection_info(FAULT_ALLOC_NID);
 		return false;
 	}
-#endif
+
 	spin_lock(&nm_i->nid_list_lock);
 
 	if (unlikely(nm_i->available_nids == 0)) {