fs: ubifs: replace CURRENT_TIME_SEC with current_time

fs: ubifs: replace CURRENT_TIME_SEC with current_time

CURRENT_TIME_SEC is not y2038 safe.  current_time() will be transitioned
to use 64 bit time along with vfs in a separate patch.  There is no plan
to transition CURRENT_TIME_SEC to use y2038 safe time interfaces.

current_time() returns timestamps according to the granularities set in
the inode's super_block.  The granularity check to call
current_fs_time() or CURRENT_TIME_SEC is not required.

Use current_time() directly to update inode timestamp.  Use
timespec_trunc during file system creation, before the first inode is
created.

Link: http://lkml.kernel.org/r/1491613030-11599-9-git-send-email-deepa.kernel@gmail.com
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: Richard Weinberger <richard@nod.at>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>