qemu: Fix migration without parameters

The virTypedParamsFilter function doesn't mind params == NULL if nparams
is zero. And there's no need to check for params == NULL && nparams > 0
because this is checked higher in the stack.

In fact all the virCheckNonNull* checks in virTypedParamsFilter are
useless.

https://bugzilla.redhat.com/show_bug.cgi?id=1777094Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NDaniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: NErik Skultety <eskultet@redhat.com>

src/util/virtypedparam.c

@@ -403,10 +403,6 @@ virTypedParamsFilter(virTypedParameterPtr params,
 {
     size_t i, n = 0;
 
-    virCheckNonNullArgGoto(params, error);
-    virCheckNonNullArgGoto(name, error);
-    virCheckNonNullArgGoto(ret, error);
-
     if (VIR_ALLOC_N(*ret, nparams) < 0)
         goto error;