MTL/PSM2: Do not lower the priority when all processes are local.

The intention of lowering the priority when all processes are local
was to favor Vader BTL. However, in builds including the OFI MTL it
gets selected instead.

Reviewed-by: Spruit, Neil R <neil.r.spruit@intel.com>
Reviewed-by: Gopalakrishnan, Aravind <aravind.gopalakrishnan@intel.com>
Signed-off-by: Matias Cabral <matias.a.cabral@intel.com>
(cherry picked from commit fc8582c5606b7a3d1b711f8f7b6144808290a48f)

ompi/mca/mtl/psm2/mtl_psm2_component.c

@@ -124,10 +124,6 @@ ompi_mtl_psm2_component_register(void)
          * process assume it is ompi_info or this is most likely going to spawn, for
          * which all PSM2 devices are needed */
         setenv("PSM2_DEVICES", "self,shm", 0);
-        /* ob1 is much faster than psm2 with shared memory */
-        param_priority = 10;
-    } else {
-        param_priority = 40;
     }
 
     (void) mca_base_component_var_register (&mca_mtl_psm2_component.super.mtl_version,