f2fs: remove unnecessary gc option check and balance_fs

 1. If f2fs is mounted with background_gc_off option, checking
    BG_GC is not redundant.
 2. f2fs_balance_fs is checked in f2fs_gc, so this is also redundant.

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 375e69e..8d293cb 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -49,11 +49,6 @@
 			continue;
 		}
 
-		f2fs_balance_fs(sbi);
-
-		if (!test_opt(sbi, BG_GC))
-			continue;
-
 		/*
 		 * [GC triggering condition]
 		 * 0. GC is not conducted currently.
@@ -96,6 +91,8 @@
 {
 	struct f2fs_gc_kthread *gc_th;
 
+	if (!test_opt(sbi, BG_GC))
+		return 0;
 	gc_th = kmalloc(sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
 	if (!gc_th)
 		return -ENOMEM;