Drop profile_ filename prefix for named profiles

Historically, if you create a `profile foo /bin/foo` with aa-logprof (by
choosing "named exec"), it will be saved as `/etc/apparmor.d/profile_foo`

This patch drops the `profile_` filename prefix so that the filename
will be `/etc/apparmor.d/foo`

utils/apparmor/aa.py

@@ -237,7 +237,7 @@ def get_new_profile_filename(profile):
         # Remove leading /
         filename = profile[1:]
     else:
-        filename = "profile_" + profile
+        filename = profile
     filename = filename.replace('/', '.')
     filename = os.path.join(profile_dir, filename)
     return filename