ipmi: use correct string length

gcc-8 reports

drivers/char/ipmi/ipmi_msghandler.c: In function
'panic_op_write_handler':
./include/linux/string.h:245:9: warning: '__builtin_strncpy' specified
bound 16 equals destination size [-Wstringop-truncation]

drivers/char/ipmi/ipmi_watchdog.c: In function 'set_param_str':
./include/linux/string.h:245:9: warning: '__builtin_strncpy' specified
bound 16 equals destination size [-Wstringop-truncation]

We need one less byte or call strlcpy() to make it a nul-terminated
string.
Signed-off-by: NXiongfeng Wang <xiongfeng.wang@linaro.org>
Signed-off-by: NCorey Minyard <cminyard@mvista.com>

drivers/char/ipmi/ipmi_msghandler.c

@@ -84,7 +84,7 @@ static int panic_op_write_handler(const char *val,
 	char valcp[16];
 	char *s;
 
-	strncpy(valcp, val, 16);
+	strncpy(valcp, val, 15);
 	valcp[15] = '\0';
 
 	s = strstrip(valcp);

drivers/char/ipmi/ipmi_watchdog.c

@@ -232,7 +232,7 @@ static int set_param_str(const char *val, const struct kernel_param *kp)
 	char       valcp[16];
 	char       *s;
 
-	strncpy(valcp, val, 16);
+	strncpy(valcp, val, 15);
 	valcp[15] = '\0';
 
 	s = strstrip(valcp);