efreet: Fix resource leak

Summary:
Coverity reports that we leak 'exec' here when we return. Add
IF_FREE(exec) to remove the leak.

Fixes Coverity CID1399090

@fix

Depends on D8353

Reviewers: raster, cedric, zmike, bu5hm4n, stefan_schmidt

Reviewed By: cedric

Subscribers: #reviewers, #committers

Tags: #efl

Differential Revision: https://phab.enlightenment.org/D8354

src/lib/efreet/efreet_desktop_command.c

@@ -464,6 +464,7 @@ efreet_desktop_command_build(Efreet_Desktop_Command *command)
     }
     while ((l = eina_list_next(l)));
 
+    IF_FREE(exec);
     return execs;
 error:
     IF_FREE(exec);