bcol/basesmuma: close mmapped file descriptor

Not closing this file descriptor will cause us to leak file
descriptors. It is safe to close the file after it has been mmapped.

cmr=v1.8.2:reviewer=manjugv

This commit was SVN r31579.

ompi/mca/bcol/basesmuma/bcol_basesmuma_smcm.c

@@ -383,6 +383,8 @@ bcol_basesmuma_smcm_mmap_t *bcol_basesmuma_smcm_mem_reg(void *in_ptr,
             return NULL;
         }
     }
+    /* no longer need this file descriptor. close it */
+    close (fd);
 
     /* takes us to the top of the control structure */