megaraid_sas: remove redundant memset call

struct fusion_context *fusion is already memset to '0', so remove a
redundant call to memmset "fusion->load_balance_info" to '0'.

Signed-off-by: Chaitra Basappa <chaitra.basappa@avagotech.com>
Signed-off-by: Sumit Saxena <sumit.saxena@avagotech.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>