Sensors: change SYSFS_MAXLEN to 50
Sensors: change SYSFS_MAXLEN to 50

SYSFS_MAXLEN decides the maxminum length of the string read from
/sys/class/sensors. Some sensor sysfs nodes may have contents
longer than 20.  This will cause the sensor_t structure not correctly
pass to framework. Expand it to 50 to fix this issue.

Change-Id: I260bbdc31fbaafb7377c72c073ef6db62d5f111b

redmi2/android_hardware_qcom_sensors,TheStrix/platform-hardware-qcom-sensors,redmi2/android_hardware_qcom_sensors,TheStrix/platform-hardware-qcom-sensors,dianlujitao/platform_hardware_qcom_sensors,dianlujitao/platform_hardware_qcom_sensors