staging/lustre/llite: don't check for O_CREAT in it_create_mode

ll_lookup_it() checks for O_CREAT in struct lookup_intent's
it_create_mode member which is nonsensical, as it_create_mode is used
for file mode bits (S_IFREG, S_IRUSR, ...). Fix this by just checking
for IT_CREATE in it_op. This will not affect the behavior of either
function, since if O_CREATE (0100) is actually set in o_create_mode
then IT_CREATE must have been set in it_op. In ll_atomic_open() check
for O_CREAT in the open_flags parameter rather than testing mode.

Lustre-change: http://review.whamcloud.com/6786
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-3517


Signed-off-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Lai Siyao <lai.siyao@intel.com>
Reviewed-by: Peng Tao <bergwolf@gmail.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Peng Tao <bergwolf@gmail.com>
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>