test/ceph_decoder: add return value check for read_file()

check the return value of read_file function call

Signed-off-by: Xing Lin <xinglin@cs.utah.edu>
test/filestore/workloadgen: added check of return value for mkdir

check return value of mkdir

Signed-off-by: Xing Lin <xinglin@cs.utah.edu>

test/filestore/workloadgen: fix return value check for mkdir

allow EEXIST from mkdir()

Signed-off-by: Xing Lin <xinglin@cs.utah.edu>
test/filestore: add check of return values in StoreTest::SetUp

add return value check for function calls, including mkdir, mkfs
and mount

Signed-off-by: Xing Lin <xinglin@cs.utah.edu>

test/filestore: fix return value check for mkdir

allow EEXIST from mkdir()

Signed-off-by: Xing Lin <xinglin@cs.utah.edu>
os/WBThrottle: added check of return value for posix_fadvise()

check the return value of posix_fadvise() in WBThrottle::entry()

Signed-off-by: Xing Lin <xinglin@cs.utah.edu>
rgw/rgw_op: added check of return value for rgw_unlink_bucket()

checked the return value of rgw_unlink_bucket() in RGWCreateBucket::execute()

Signed-off-by: Xing Lin <xinglin@cs.utah.edu>
test/mon/workloadgen: added check of return value for statfs()

check the return value of statfs() in update_osd_stat()

Signed-off-by: Xing Lin <xinglin@cs.utah.edu>

test/mon/workloadgen: fixed typo in error message

Signed-off-by: Xing Lin <xinglin@cs.utah.edu>
Merge pull request #879 from xinglin/coverity-fixes

Coverity fixes

The rgw patch is
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>

The rest is
Reviewed-by: Sage Weil <sage@inktank.com>