Fixes trac:1365: if we're using !^ to negate module inclusion, then don't

bother to check to see whether they exist or not.  Specifically, this
will not cause an error:

{{{
shell$ mpirun --mca btl ^does_not_exist ...
}}}

but neither will this:

{{{
shell$ mpirun --mca btl ^sm ...
}}}

(where the sm BTL ''does'' exist)

This commit was SVN r18760.

The following Trac tickets were found above:
  Ticket 1365 --> https://svn.open-mpi.org/trac/ompi/ticket/1365

opal/mca/base/mca_base_component_find.c

@@ -182,7 +182,7 @@ int mca_base_component_find(const char *directory, const char *type,
 
     /* Ensure that *all* requested components exist.  Print a warning
        and abort if they do not. */
-    for (i = 0; NULL != requested_component_names && 
+    for (i = 0; include_mode && NULL != requested_component_names && 
              NULL != requested_component_names[i]; ++i) {
         for (item = opal_list_get_first(found_components);
              opal_list_get_end(found_components) != item;