osd/erasurecode: correct one variable name in jerasure_matrix_to_bitmatrix()

When bitmatrix is NULL, this function returns NULL.

Signed-off-by: Xing Lin <xinglin@cs.utah.edu>
mon/MDSMonitor: remove unnecessary assignment

epocharg is not initialized, so it does not make any difference
to assign its value to epoch.

Signed-off-by: Xing Lin <xinglin@cs.utah.edu>
osd/erasurecode: free allocated memory before return NULL

free memory space pointed by row_ids and ind_to_row before return

Signed-off-by: Xing Lin <xinglin@cs.utah.edu>
osd/ErasureCodePlugin: close library before return on error

close and free resources for library before return

Signed-off-by: Xing Lin <xinglin@cs.utah.edu>
Merge pull request #819 from xinglin/coverity-fixes

Coverity fixes

Reviewed-by; Sage Weil <sage@inktank.com>