mtd: core: Report error if first mtd_otp_size() call fails in mtd_otp_nvmem_add()

Jump to the error reporting code in mtd_otp_nvmem_add() if the
mtd_otp_size() call fails. Without this fix, the error is not logged.

Signed-off-by: Aapo Vienamo <aapo.vienamo@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Michael Walle <mwalle@kernel.org>
Fixes: 4b361cfa

 ("mtd: core: add OTP nvmem provider support")
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20240313173425.1325790-2-aapo.vienamo@linux.intel.com