platform: msm_shared: allocate global transfer descriptor for usb

Transfer descriptor items will be allocated for every flash command
and not freed by the usb code. So leads to in sufficient memory for
any new memory allocation. Modified code to use global transfer
descriptor instead of creating a new one everytime.

Change-Id: I7f60209f87cc3b8e3ccd509aaf09a7ffe190332c
1 file changed