staging: exfat: remove sync_alloc_bitmap()

sync_alloc_bitmap() is not called anywhere, hence remove it from
exfat_core.c and exfat.h
Signed-off-by: Kaaira Gupta <kgupta@es.iitr.ac.in>
Link: https://lore.kernel.org/r/20200223192347.GA20286@kaaira-HP-Pavilion-NotebookSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/exfat/exfat.h

@@ -666,7 +666,6 @@ void exfat_chain_cont_cluster(struct super_block *sb, u32 chain, s32 len);
 /* allocation bitmap management functions */
 s32 load_alloc_bitmap(struct super_block *sb);
 void free_alloc_bitmap(struct super_block *sb);
-void sync_alloc_bitmap(struct super_block *sb);
 
 /* upcase table management functions */
 s32 load_upcase_table(struct super_block *sb);

drivers/staging/exfat/exfat_core.c

@@ -561,18 +561,6 @@ void free_alloc_bitmap(struct super_block *sb)
 	p_fs->vol_amap = NULL;
 }
 
-void sync_alloc_bitmap(struct super_block *sb)
-{
-	int i;
-	struct fs_info_t *p_fs = &(EXFAT_SB(sb)->fs_info);
-
-	if (!p_fs->vol_amap)
-		return;
-
-	for (i = 0; i < p_fs->map_sectors; i++)
-		sync_dirty_buffer(p_fs->vol_amap[i]);
-}
-
 /*
  *  Upcase table Management Functions
  */