* src/ls.c (quote_name): Use initializer rather than memset to

* src/ls.c (quote_name): Use initializer rather than memset to
initialize an object to zero.  This is easier to read and is less
likely to introduce an runtime error due to a mixup.  It causes
gcc -W to issue a warning, but you can work around this by
appending -Wno-missing-field-initializers.
* src/pathchk.c (portable_chars_only): Likewise.
* src/shred.c (main): Likewise.
* src/stty.c (main): Likewise.
* src/tr.c (card_of_complement): Likewise.
* src/wc.c (wc): Likewise.