fat: fix unaligned errors

A couple of buffers in the fat code are declared as an array of bytes.
But it is then cast up to a structure with 16bit and 32bit members.
Since GCC assumes structure alignment here, we have to force the
buffers to be aligned according to the structure usage.

Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

fs/fat/fat.c

@@ -434,7 +434,8 @@ slot2str(dir_slot *slotptr, char *l_name, int *idx)
  * into 'retdent'
  * Return 0 on success, -1 otherwise.
  */
-__u8	 get_vfatname_block[MAX_CLUSTSIZE];
+__attribute__ ((__aligned__(__alignof__(dir_entry))))
+__u8 get_vfatname_block[MAX_CLUSTSIZE];
 static int
 get_vfatname(fsdata *mydata, int curclust, __u8 *cluster,
 	     dir_entry *retdent, char *l_name)
@@ -520,6 +521,7 @@ mkcksum(const char *str)
  * Get the directory entry associated with 'filename' from the directory
  * starting at 'startsect'
  */
+__attribute__ ((__aligned__(__alignof__(dir_entry))))
 __u8 get_dentfromdir_block[MAX_CLUSTSIZE];
 static dir_entry *get_dentfromdir (fsdata * mydata, int startsect,
 				   char *filename, dir_entry * retdent,
@@ -725,8 +727,8 @@ read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize)
 	return -1;
 }
 
-
-__u8 do_fat_read_block[MAX_CLUSTSIZE];  /* Block buffer */
+__attribute__ ((__aligned__(__alignof__(dir_entry))))
+__u8 do_fat_read_block[MAX_CLUSTSIZE];
 long
 do_fat_read (const char *filename, void *buffer, unsigned long maxsize,
 	     int dols)