mtd: rawnand: hynix: fixed typo

The function hynix_nand_rr_init() should probably return an error code.
Judging by the usage, it seems that the return code is passed up
the call stack.
Right now, it always returns 0 and the function hynix_nand_cleanup()
in hynix_nand_init() has never been called.

Found by RASU JSC and Linux Verification Center (linuxtesting.org)

Fixes: 626994e0

 ("mtd: nand: hynix: Add read-retry support for 1x nm MLC NANDs")

Signed-off-by: Maxim Korotkov <korotkov.maxim.s@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20240313102721.1991299e-1-korotkov.maxim.s@gmail.com