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/file.c b/fs/f2fs/file.c
index 4a6f604..bd25d59 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -670,12 +670,11 @@
 
 	trace_f2fs_truncate(inode);
 
-#ifdef CONFIG_F2FS_FAULT_INJECTION
 	if (time_to_inject(F2FS_I_SB(inode), FAULT_TRUNCATE)) {
 		f2fs_show_injection_info(FAULT_TRUNCATE);
 		return -EIO;
 	}
-#endif
+
 	/* we should check inline_data size */
 	if (!f2fs_may_inline_data(inode)) {
 		err = f2fs_convert_inline_inode(inode);