LOCAL / net: bcmdbd: call vfs functions instead of direct file ops

LOCAL / net: bcmdbd: call vfs functions instead of direct file ops

This patch was made by reference to Przemyslaw Marczak's patch
on linux-exynos repository of Tizen Git.

  LOCAL / net: bcm4358: call vfs functions instead of direct file ops
  author	Przemyslaw Marczak <p.marczak@samsung.com>
  Mon, 2 Nov 2015 23:16:27 +0900 (15:16 +0100)
  committer	Marek Szyprowski <m.szyprowski@samsung.com>
  Mon, 16 May 2016 16:19:57 +0900 (09:19 +0200)
  commit	a0ca5befacaa52b9b876dee29c1b3db1e61fac24

  LOCAL / net: bcm4358: call vfs functions instead of direct file ops

  After enable writing the card's MAC address to filesystem by:

  commit: LOCAL / net: bcm4358: Enable the some configurations

  in the driver's code for bcmdhd4358, filesystem access is required
  to read/write some settings, especially the card's MAC address.

  Instead of calling proper fs functions, a direct calls were used
  to particular file operations methods.
  Since read/write operations are deprecated, the present code without
  null pointer checking, refers to null function pointers.
  This causes kernel panic when runs wpa_supplicant application.

  This commit moves the direct calls to proper function calls,
  which fixes the panic issue.

Change-Id: If964fc062a7ec791658a92930b48263bd474ffcb
Signed-off-by: jino.cho <jino.cho@samsung.com>