MINOR: threads/plock: rename local variables in macros to avoid conflicts

[ plock commit b155d5c762fb9a9793911881f80e61faa6b0e889 ]

Local variables "l", "i" and "ret" were renamed "__pl_l", "__pl_i" and
"__pl_r" respectively, to limit the risk of conflicts with existing
variables in application code.
1 file changed