ata: fix sparse warnings in pata_legacy.c

Use ld_qdi and ld_winbond to avoid shadowing static int
variables qdi and winbond.  The ld_ prefix refers to
legacy_data.

drivers/ata/pata_legacy.c:777:21: warning: symbol 'qdi' shadows an earlier one
drivers/ata/pata_legacy.c:128:12: originally declared here
drivers/ata/pata_legacy.c:811:21: warning: symbol 'qdi' shadows an earlier one
drivers/ata/pata_legacy.c:128:12: originally declared here
drivers/ata/pata_legacy.c:848:21: warning: symbol 'qdi' shadows an earlier one
drivers/ata/pata_legacy.c:128:12: originally declared here
drivers/ata/pata_legacy.c:882:21: warning: symbol 'qdi' shadows an earlier one
drivers/ata/pata_legacy.c:128:12: originally declared here
drivers/ata/pata_legacy.c:1040:21: warning: symbol 'winbond' shadows an earlier one
drivers/ata/pata_legacy.c:129:12: originally declared here

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>