UBIFS: endian handling fixes and annotations

Noticed by sparse:
fs/ubifs/file.c:75:2: warning: restricted __le64 degrades to integer
fs/ubifs/file.c:629:4: warning: restricted __le64 degrades to integer
fs/ubifs/dir.c:431:3: warning: restricted __le64 degrades to integer

This should be checked to ensure the ubifs_assert is working as
intended, I've done the suggested annotation in this patch.

fs/ubifs/sb.c:298:6: warning: incorrect type in assignment (different base types)
fs/ubifs/sb.c:298:6:    expected int [signed] [assigned] tmp
fs/ubifs/sb.c:298:6:    got restricted __le64 [usertype] <noident>
fs/ubifs/sb.c:299:19: warning: incorrect type in assignment (different base types)
fs/ubifs/sb.c:299:19:    expected restricted __le64 [usertype] atime_sec
fs/ubifs/sb.c:299:19:    got int [signed] [assigned] tmp
fs/ubifs/sb.c:300:19: warning: incorrect type in assignment (different base types)
fs/ubifs/sb.c:300:19:    expected restricted __le64 [usertype] ctime_sec
fs/ubifs/sb.c:300:19:    got int [signed] [assigned] tmp
fs/ubifs/sb.c:301:19: warning: incorrect type in assignment (different base types)
fs/ubifs/sb.c:301:19:    expected restricted __le64 [usertype] mtime_sec
fs/ubifs/sb.c:301:19:    got int [signed] [assigned] tmp

This looks like a bugfix as your tmp was a u32 so there was truncation in
the atime, mtime, ctime value, probably not intentional, add a tmp_le64
and use it here.

fs/ubifs/key.h:348:9: warning: cast to restricted __le32
fs/ubifs/key.h:348:9: warning: cast to restricted __le32
fs/ubifs/key.h:419:9: warning: cast to restricted __le32

Read from the annotated union member instead.

fs/ubifs/recovery.c:175:13: warning: incorrect type in assignment (different base types)
fs/ubifs/recovery.c:175:13:    expected unsigned int [unsigned] [usertype] save_flags
fs/ubifs/recovery.c:175:13:    got restricted __le32 [usertype] flags
fs/ubifs/recovery.c:186:13: warning: incorrect type in assignment (different base types)
fs/ubifs/recovery.c:186:13:    expected restricted __le32 [usertype] flags
fs/ubifs/recovery.c:186:13:    got unsigned int [unsigned] [usertype] save_flags

Do byteshifting at compile time of the flag value.  Annotate the saved_flags
as le32.

fs/ubifs/debug.c:368:10: warning: cast to restricted __le32
fs/ubifs/debug.c:368:10: warning: cast from restricted __le64

Should be checked if the truncation was intentional, I've changed the
printk to print the full width.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>