Merge pull request #13175 from hppritcha/swat_xhc_comp_warning

XHC: swat compiler warning bug

Author: hppritcha

ompi/mca/coll/xhc/coll_xhc_component.c

@@ -210,7 +210,7 @@ static int xhc_register(void) {
     int var_index = mca_base_var_find("opal", "smsc", "xpmem", "memcpy_chunk_size");
 
     if(var_index >= 0) {
-        size_t *var_value_ptr;
+        size_t *var_value_ptr = NULL;
 
         err = mca_base_var_get_value(var_index, &var_value_ptr, NULL, NULL);