btl/tcp: fix minor memory leak

split_and_resolve() destroys an argv as it analyzes it.  Fix one case
in the loop where argv[i] was accidentally neglected to be freed.

Signed-off-by: Jeff Squyres <[email protected]>
(cherry picked from commit 1395303)

opal/mca/btl/tcp/btl_tcp_component.c

@@ -668,6 +668,7 @@ static char **split_and_resolve(char **orig_str, char *name, bool reqd)
                                     "btl: tcp: Using interface: %s ", argv[i]);
                 opal_argv_append(&interface_count, &interfaces, argv[i]);
             }
+            free(argv[i]);
             continue;
         }