[ssd] NameError: nand_endurance undefined in parse_micron_info()

[rustiqly]

Description

In sonic_platform_base/sonic_storage/ssd.py, around line 345, parse_micron_info() references nand_endurance which is never defined in that method. The variable only exists in parse_virtium_info().

Current code

self.health = 100 - (float(average_erase_count) * 100 / float(nand_endurance))
# nand_endurance is ONLY defined in parse_virtium_info(), not here

Impact

NameError at runtime for Micron SSDs when the primary health attribute is unavailable and the code falls back to computing health from average erase count.

Fix

Define nand_endurance from the appropriate Micron SMART attribute before using it in the calculation.