Make printf and vprintf safe from buffer overruns

From: Sonny Rao <sonnyrao@chromium.org>

utilize the added vscnprintf functions to avoid buffer overruns
The implementation is fairly dumb in that it doesn't detect
that the buffer is too small, but at least will not cause crashes.

Signed-off-by: Sonny Rao <sonnyrao@chromium.org>
diff --git a/common/console.c b/common/console.c
index d34a0f4..1d9fd7f 100644
--- a/common/console.c
+++ b/common/console.c
@@ -212,7 +212,7 @@
 	/* For this to work, printbuffer must be larger than
 	 * anything we ever want to print.
 	 */
-	i = vsprintf(printbuffer, fmt, args);
+	i = vscnprintf(printbuffer, sizeof(printbuffer), fmt, args);
 	va_end(args);
 
 	serial_puts(printbuffer);
@@ -281,7 +281,7 @@
 	/* For this to work, printbuffer must be larger than
 	 * anything we ever want to print.
 	 */
-	i = vsprintf(printbuffer, fmt, args);
+	i = vscnprintf(printbuffer, sizeof(printbuffer), fmt, args);
 	va_end(args);
 
 	/* Send to desired file */
@@ -434,7 +434,7 @@
 	/* For this to work, printbuffer must be larger than
 	 * anything we ever want to print.
 	 */
-	i = vsprintf(printbuffer, fmt, args);
+	i = vscnprintf(printbuffer, sizeof(printbuffer), fmt, args);
 	va_end(args);
 
 	/* Print the string */
@@ -455,7 +455,7 @@
 	/* For this to work, printbuffer must be larger than
 	 * anything we ever want to print.
 	 */
-	i = vsprintf(printbuffer, fmt, args);
+	i = vscnprintf(printbuffer, sizeof(printbuffer), fmt, args);
 
 	/* Print the string */
 	puts(printbuffer);
@@ -522,7 +522,7 @@
 	/* For this to work, printbuffer must be larger than
 	 * anything we ever want to print.
 	 */
-	i = vsprintf(printbuffer, fmt, args);
+	i = vsnprintf(printbuffer, sizeof(printbuffer), fmt, args);
 	va_end(args);
 
 	if ((screen + sizeof(screen) - 1 - cursor)