Use msleep() to avoid lost wakeup's instead of doing an ineffective splhigh() before the mtx_unlock and tsleep().  The splhigh() was probably correct in the original code using simplelocks but is not correct in 5.0-current.
Use msleep() to avoid lost wakeup's instead of doing an ineffective
splhigh() before the mtx_unlock and tsleep().  The splhigh() was probably
correct in the original code using simplelocks but is not correct in
5.0-current.

Noticed by:	Andrew Reiter <awr@FreeBSD.org>

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase