Revert "osc/pt2pt: use two distinct "namespaces" for tags"

This reverts commit 06ecdb6aa7ee688f51de2b3ca05e9f0605a90099
to reimplement the fix completely.

ompi/mca/osc/pt2pt/osc_pt2pt.h

@@ -150,7 +150,6 @@ struct ompi_osc_pt2pt_module_t {
 
     /** cyclic counter for a unique tage for long messages. */
     uint32_t tag_counter;
-    uint32_t rtag_counter;
 
     /* Number of outgoing fragments that have completed since the
        begining of time */
@@ -650,18 +649,10 @@ static inline int get_tag(ompi_osc_pt2pt_module_t *module)
     /* the LSB of the tag is used be the receiver to determine if the
        message is a passive or active target (ie, where to mark
        completion). */
-    int32_t tmp = OPAL_THREAD_ADD32((volatile int32_t *) &module->tag_counter, 4);
+    int32_t tmp = OPAL_THREAD_ADD32((volatile int32_t *) &module->tag_counter, 2);
     return (tmp & OSC_PT2PT_FRAG_MASK) | !!(module->passive_target_access_epoch);
 }
 
-static inline int get_rtag(ompi_osc_pt2pt_module_t *module)
-{
-    /* the LSB of the tag is used be the receiver to determine if the
-       message is a passive or active target (ie, where to mark
-       completion). */
-    int32_t tmp = OPAL_THREAD_ADD32((volatile int32_t *) &module->rtag_counter, 4);
-    return (tmp & OSC_PT2PT_FRAG_MASK) | !!(module->passive_target_access_epoch);
-}
 /**
  * ompi_osc_pt2pt_accumulate_lock:
  *

ompi/mca/osc/pt2pt/osc_pt2pt_comm.c

@@ -491,7 +491,7 @@ ompi_osc_pt2pt_accumulate_w_req (const void *origin_addr, int origin_count,
          }
 
         is_long_msg = true;
-        tag = get_rtag (module);
+        tag = get_tag (module);
     }
 
     if (is_long_msg) {

ompi/mca/osc/pt2pt/osc_pt2pt_component.c

@@ -290,7 +290,6 @@ component_select(struct ompi_win_t *win, void **base, size_t size, int disp_unit
     /* fill in the function pointer part */
     memcpy(module, &ompi_osc_pt2pt_module_template,
            sizeof(ompi_osc_base_module_t));
-    module->rtag_counter = 2;
 
     /* initialize the objects, so that always free in cleanup */
     OBJ_CONSTRUCT(&module->lock, opal_mutex_t);