ipmi: use USEC_PER_SEC instead of 1000000 for more meaningful

Use USEC_PER_SEC instead of 1000000, that making the later bugfix
more clearly.

Signed-off-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/char/ipmi/ipmi_smic_sm.c b/drivers/char/ipmi/ipmi_smic_sm.c
index faed929..c8e77af 100644
--- a/drivers/char/ipmi/ipmi_smic_sm.c
+++ b/drivers/char/ipmi/ipmi_smic_sm.c
@@ -80,7 +80,7 @@
 #define SMIC_MAX_ERROR_RETRIES 3
 
 /* Timeouts in microseconds. */
-#define SMIC_RETRY_TIMEOUT 2000000
+#define SMIC_RETRY_TIMEOUT (2*USEC_PER_SEC)
 
 /* SMIC Flags Register Bits */
 #define SMIC_RX_DATA_READY	0x80