Fixed namespace pollution in uma changes: - use `struct uma_zone *' instead of uma_zone_t, so that <sys/uma.h> isn't   a prerequisite. - don't include <sys/uma.h>. Namespace pollution makes "opaque" types like uma_zone_t perfectly non-opaque.  Such types should never be used (see style(9)).
Fixed namespace pollution in uma changes:
- use `struct uma_zone *' instead of uma_zone_t, so that <sys/uma.h> isn't
  a prerequisite.
- don't include <sys/uma.h>.
Namespace pollution makes "opaque" types like uma_zone_t perfectly
non-opaque.  Such types should never be used (see style(9)).

Fixed subsequently grwon dependencies of this header on its own pollution:
- include <sys/_mutex.h> and its prerequisite <sys/_lock.h> instead of
  depending on namespace pollution 2 layers deep in <sys/uma.h>.

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