Don't do bad things for empty mfcc files



git-svn-id: svn+ssh://svn.code.sf.net/p/cmusphinx/code/trunk/pocketsphinx@12606 94700074-3cef-4d97-a70e-9c8c206c02f5
Even less duplicated information.
Thanks to Halle Winkler.



git-svn-id: svn+ssh://svn.code.sf.net/p/cmusphinx/code/trunk/pocketsphinx@12608 94700074-3cef-4d97-a70e-9c8c206c02f5