hwmon: (macsmc) Fix regressions in Apple Silicon SMC hwmon driver

In the Linux kernel, the following vulnerability has been resolved:

hwmon: (macsmc) Fix regressions in Apple Silicon SMC hwmon driver

The recently added macsmc-hwmon driver contained several critical

bugs in its sensor population logic and float conversion routines.

Specifically:

- The voltage sensor population loop used the wrong prefix ("volt-"

instead of "voltage-") and incorrectly assigned sensors to the

temperature sensor array (hwmon->temp.sensors) instead of the

voltage sensor array (hwmon->volt.sensors). This would lead to

out-of-bounds memory access or data corruption when both temperature

and voltage sensors were present.

- The float conversion in macsmc_hwmon_write_f32() had flawed exponent

logic for values >= 2^24 and lacked masking for the mantissa, which

could lead to incorrect values being written to the SMC.

Fix these issues to ensure correct sensor registration and reliable

manual fan control.

Confirm that the reported overflow in FIELD_PREP is fixed by declaring

macsmc_hwmon_write_f32() as __always_inline for a compile test.