GCC4.6: Squash warnings in onenand_base.c

onenand_base.c: In function ‘onenand_do_lock_cmd’:
onenand_base.c:1946:6: warning: variable ‘wp_status_mask’ set but not used
[-Wunused-but-set-variable]
onenand_base.c: In function ‘onenand_check_maf’:
onenand_base.c:2229:8: warning: variable ‘name’ set but not used
[-Wunused-but-set-variable]
onenand_base.c: In function ‘flexonenand_get_boundary’:
onenand_base.c:2258:6: warning: variable ‘ret’ set but not used
[-Wunused-but-set-variable]

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Scott Wood <scottwood@freescale.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>