f2fs: fix to account preflush command for noflush_merge mode

Previously, we only account preflush command for flush_merge mode,
so for noflush_merge mode, we can not know in-flight preflush
command count, fix it.

Signed-off-by: Chao Yu <[e-mail]>
Signed-off-by: Jaegeuk Kim <[e-mail]>

fs/f2fs/segment.c

···
 		return 0;
 
 	if (!test_opt(sbi, FLUSH_MERGE)) {
+		atomic_inc(&fcc->issing_flush);
 		ret = submit_flush_wait(sbi, ino);
+		atomic_dec(&fcc->issing_flush);
 		atomic_inc(&fcc->issued_flush);
 		return ret;
 	}