Revert "block: Fix use-after-free while iterating over requests"

commit 10ee57c2 ("block: Fix use-after-free while iterating over
requests")
This is needed to fix regression observed in suspend/resume
paths where the tag corresponds to static_rqs is becoming
NULL and observed a kernel panic due to NULL pointer access in
blk_mq_get_rq().

89.824342:   <2> Call trace:
89.824356:   <2>  blk_mq_get_request+0x200/0x3ec
89.824367:   <2>  blk_mq_alloc_request+0x5c/0xb4
89.824382:   <2>  blk_get_request+0x2c/0xa4
89.824398:   <2>  __scsi_execute+0x58/0x1a0
89.824413:   <2>  ufshcd_set_dev_pwr_mode+0x174/0x248
89.824425:   <2>  ufshcd_suspend+0x2e8/0x830
89.824436:   <2>  ufshcd_runtime_suspend+0x44/0x194
89.824452:   <2>  ufshcd_pltfrm_runtime_suspend+0x14/0x20
89.824468:   <2>  pm_generic_runtime_suspend+0x44/0x80
89.824481:   <2>  __rpm_callback+0x98/0x1d8
89.824493:   <2>  rpm_suspend+0x31c/0x634
89.824505:   <2>  rpm_idle+0x158/0x228.

Change-Id: I5bc3d75a9d891054dc926171b3ad90b701d776d6
Signed-off-by: Pradeep P V K <pragalla@codeaurora.org>