rtlwifi: Fix scheduling while atomic error from commit 49f86ec21c01

rtlwifi: Fix scheduling while atomic error from commit 49f86ec21c01

Commit 49f86ec21c01 ("rtlwifi: Change long delays to sleeps") was correct
for most cases; however, driver rtl8192ce calls the affected routines while
in atomic context. The kernel bug output is as follows:

BUG: scheduling while atomic: wpa_supplicant/627/0x00000002
[...]
  [<ffffffff815c2b39>] __schedule+0x899/0xad0
  [<ffffffff815c2dac>] schedule+0x3c/0x90
  [<ffffffff815c5bb2>] schedule_hrtimeout_range_clock+0xa2/0x120
  [<ffffffff810e8b80>] ? hrtimer_init+0x120/0x120
  [<ffffffff815c5ba6>] ? schedule_hrtimeout_range_clock+0x96/0x120
  [<ffffffff815c5c43>] schedule_hrtimeout_range+0x13/0x20
  [<ffffffff815c568f>] usleep_range+0x4f/0x70
  [<ffffffffa0667218>] rtl_rfreg_delay+0x38/0x50 [rtlwifi]
  [<ffffffffa06dd0e7>] rtl92c_phy_config_rf_with_headerfile+0xc7/0xe0 [rtl8192ce]

To fix this bug, three of the changes from delay to sleep are reverted.
Unfortunately, one of the changes involves a delay of 50 msec. The calling
code will be modified so that this long delay can be avoided; however,
this change is being pushed now to fix the problem in kernel 4.6.0.

Fixes: 49f86ec21c01 ("rtlwifi: Change long delays to sleeps")
Reported-by: James Feeney <james@nurealm.net>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: James Feeney <james@nurealm.net>
Cc: Stable <stable@vger.kernel.org> [4.6+]
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>