Revert "usb: msm7k_udc: Add delay upon request dequeue failure"

This reverts commit 00395687.

Reverting this commit due to the following reasons

1. Throughputs numbers on the DUN interface has degraded with this change
2. Data stall issue that was fixed with this change is occuring only on
   agilent setup and not reproducible on BOA setup.
3. Issue 1 is identified as critical than Issue 2.

Conflicts:

        drivers/usb/gadget/msm72k_udc.c

CRs-Fixed: 334938
Change-Id: I1cc745a3bebe6f6b97b170138b4643db50b7e516
Signed-off-by: Chiranjeevi Velempati <cvelempa@codeaurora.org>