datamodel_errors: generalize error for sr_suspend_space_insufficient (#6851)

The error can be produced while doing a suspend, not only on
checkpoints. Remove the last sentence so it applied in both cases

Author: psafont

ocaml/idl/datamodel_errors.ml

@@ -1119,7 +1119,7 @@ let _ =
   error Api_errors.sr_suspend_space_insufficient ["sr"]
     ~doc:
       "The suspend SR does not have sufficient free space to store the VM \
-       suspend image required to complete a snapshot with memory."
+       suspend image."
     () ;
   error Api_errors.pbd_exists ["sr"; "host"; "pbd"]
     ~doc:"A PBD already exists connecting the SR to the server." () ;