firewire: ohci: use common buffer for self IDs and AR descriptors
firewire: ohci: use common buffer for self IDs and AR descriptors

The buffers used for the selfIDs packets and the AR request and response
descriptors end up using three pages because dma_alloc_coherent()
allocates at least one page per call.  However, these data structures
would all fit into 4 KB, so we can save space by using a common buffer
for them.

Signed-off-by: Clemens Ladisch <9f57ef5ff1095f40b1ee8b7caa363908baef59d7@ladisch.de>
Signed-off-by: Stefan Richter <fbd796546fc801b34e01e453c6fd30283e012038@s5r6.in-berlin.de>

KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs