Corrected /data mount point detection in disk statistics

[wildmer]

Disk statistics were not working correctly on my device. After investigating the issue, I noticed that /data was missing from the list of mount points. However, there was a match with /product/data-app, which likely caused the error.

Example output from the df -h command:

  overlay                             12K  12K     0 100%  /product/data-app
  /dev/fuse                          475G 138G  337G  30%  /storage/emulated

To fix this, I modified the mount point detection logic for /data, ensuring that any incorrect matches with overlay are excluded and setting a default value if /data is not found.

Code Changes:

  dir=$(df -h | grep '/data' | grep -v 'overlay' | awk '{print $6}')

  if [ -z "$dir" ]; then
      dir="storage/emulated"
  fi
  _MOUNTED_ON="$dir"

With this change, /data mount point detection is more accurate and should prevent issues on devices where /data does not appear directly in the df -h output. This could solve the issue #76

Attached is a screenshot showing the detected issue: