libsepol: destroy the copied va_list

va_copy()'s manpage [1] states:

    Each invocation of va_copy() must be matched by a corresponding
    invocation of va_end() in the same function.

create_str_helper() is using va_copy() without va_end(). Add the missing
call.

[1] https://linux.die.net/man/3/va_copy

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>

libsepol/src/kernel_to_common.c

@@ -80,10 +80,13 @@ static char *create_str_helper(const char *fmt, int num, va_list vargs)
 		goto exit;
 	}
 
+	va_end(vargs2);
+
 	return str;
 
 exit:
 	free(str);
+	va_end(vargs2);
 	return NULL;
 }