Fix changing hash key after module is inserted in hash

Fix changing hash key after module is inserted in hash

The hash key is not copied so we can't change the string from:
	modname/modalias

	to:

	modname'\0'modalias

in order to setup mod->name and mod->alias.

Now what we do is:

1) if name is in the form 'modname/modalias', the final struct
   kmod_module will be:

   struct kmod_module {
           char *alias;------,
           char *name;-----, |
           char *hashkey;--|-|-,
   }                       | | |
   name <------------------' | |
   alias <-------------------' |
   hashkey <-------------------'

2) if name is in the simple form 'modname', then the final struct
   kmod_module will be:

   struct kmod_module {
           char *alias;------> NULL
           char *name;-----,
           char *hashkey;--|---,
   }                       |   |
   name <------------------*---'