bfa: Fix undefined bit shift on big-endian architectures with 32-bit DMA address

bfa_swap_words() shifts its argument (assumed to be 64-bit) by 32 bits
each way.  In two places the argument type is dma_addr_t, which may be
32-bit, in which case the effect of the bit shift is undefined:

drivers/scsi/bfa/bfa_fcpim.c: In function 'bfa_ioim_send_ioreq':
drivers/scsi/bfa/bfa_fcpim.c:2497:4: warning: left shift count >= width of type [enabled by default]
    addr = bfa_sgaddr_le(sg_dma_address(sg));
    ^
drivers/scsi/bfa/bfa_fcpim.c:2497:4: warning: right shift count >= width of type [enabled by default]
drivers/scsi/bfa/bfa_fcpim.c:2509:4: warning: left shift count >= width of type [enabled by default]
    addr = bfa_sgaddr_le(sg_dma_address(sg));
    ^
drivers/scsi/bfa/bfa_fcpim.c:2509:4: warning: right shift count >= width of type [enabled by default]

Avoid this by adding casts to u64 in bfa_swap_words().

Compile-tested only.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Anil Gurumurthy <anil.gurumurthy@qlogic.com>
Cc: stable@vger.kernel.org
Fixes: f16a1750 ('[SCSI] bfa: remove all OS wrappers')
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/scsi/bfa/bfa_ioc.h

@@ -72,7 +72,7 @@ struct bfa_sge_s {
 } while (0)
 
 #define bfa_swap_words(_x)  (	\
-	((_x) << 32) | ((_x) >> 32))
+	((u64)(_x) << 32) | ((u64)(_x) >> 32))
 
 #ifdef __BIG_ENDIAN
 #define bfa_sge_to_be(_x)