net: phy: mediatek: fix nvmem cell reference leak in mt798x_phy_calibration

net: phy: mediatek: fix nvmem cell reference leak in mt798x_phy_calibration

When nvmem_cell_read() fails in mt798x_phy_calibration(), the function
returns without calling nvmem_cell_put(), leaking the cell reference.

Move nvmem_cell_put() right after nvmem_cell_read() to ensure the cell
reference is always released regardless of the read result.

Found via static analysis and code review.

Fixes: 98c485eaf509 ("net: phy: add driver for MediaTek SoC built-in GE PHYs")
Cc: stable@vger.kernel.org
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Reviewed-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20251211081313.2368460-1-linmq006@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>