Set fsal_stable bool correctly in GPFSFSAL_write.

bool is a character, so we should not cast fsal_stable to uint32_t
pointer. *fsal_stable was also unchanged, so set it correctly now.

Signed-off-by: Malahal Naineni <malahal@us.ibm.com>
Merge branch 'tp/pull-request' into ibm_next_20_tmp