ipmi: Remove uses of return value of seq_printf

The seq_printf like functions will soon be changed to return void.

Convert these uses to check seq_has_overflowed instead.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>

diff --cc drivers/char/ipmi/ipmi_msghandler.c
Simple merge

diff --cc drivers/char/ipmi/ipmi_si_intf.c
Simple merge

diff --cc drivers/char/ipmi/ipmi_ssif.c
Simple merge