fix bug for gpu-mode of cdiag operator
fix bug for gpu-mode of cdiag operator

Takishima/bart,sidward/bart,sdimoudi/bart,sdimoudi/bart,sidward/bart,sdimoudi/bart,sdimoudi/bart,sidward/bart,Takishima/bart,mrirecon/bart,sdimoudi/bart,mrirecon/bart,sidward/bart,Takishima/bart,mrirecon/bart,Takishima/bart,mrirecon/bart,sidward/bart,Takishima/bart,mrirecon/bart