perf script: Remove some bogus error handling

If script_desc__new() fails then the current code has a NULL
dereference.  We don't actually need to do any cleanup, we can just
return NULL.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: kernel-janitors@vger.kernel.org
Link: http://lkml.kernel.org/r/20170722073610.nnsyiwdcfl6bhn4t@mwandaSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-script.c

@@ -2199,16 +2199,11 @@ static struct script_desc *script_desc__findnew(const char *name)
 
 	s = script_desc__new(name);
 	if (!s)
-		goto out_delete_desc;
+		return NULL;
 
 	script_desc__add(s);
 
 	return s;
-
-out_delete_desc:
-	script_desc__delete(s);
-
-	return NULL;
 }
 
 static const char *ends_with(const char *str, const char *suffix)