scsi: elx: efct: Eliminate unnecessary boolean check in efct_hw_command_cancel()

scsi: elx: efct: Eliminate unnecessary boolean check in efct_hw_command_cancel()

clang warns:

drivers/scsi/elx/efct/efct_hw.c:1523:17: warning: address of array
'ctx->buf' will always evaluate to 'true' [-Wpointer-bool-conversion]
                              (!ctx->buf ? U32_MAX : *((u32 *)ctx->buf)));
                               ~~~~~~^~~

buf is an array in the middle of a struct so deferencing it is not a
problem as long as ctx is not NULL. Eliminate the check, which fixes the
warning.

Link: https://github.com/ClangBuiltLinux/linux/issues/1398
Link: https://lore.kernel.org/r/20210617063123.21239-1-nathan@kernel.org
Fixes: 580c0255e4ef ("scsi: elx: efct: RQ buffer, memory pool allocation and deallocation APIs")
Reviewed-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>