[PATCH 4.14 063/156] drm/amdkfd: Fix SDMA ring buffer size calculation

4.14-stable review patch. If anyone has any objections, please let me know. -- From: shaoyunl [ Upstream commit d12fb13f23199faa7e536acec1db49068e5a067d ] ffs function return the position of the first bit set on 1 based. (bit zero returns 1).

[PATCH 4.14 063/156] drm/amdkfd: Fix SDMA ring buffer size calculation

4.14-stable review patch. If anyone has any objections, please let me know. -- From: shaoyunl [ Upstream commit d12fb13f23199faa7e536acec1db49068e5a067d ] ffs function return the position of the first bit set on 1 based. (bit zero returns 1). Signed-off-by: shaoyun liu