util/inteltool: Shrink buffer size

512 bytes is much too big for this buffer, which only needs to hold a
path that will have a length of at most 20. The large buffer size also
triggers a -Wformat-truncation warning with GCC since it is later
printed into the smaller temp_string array, so shrink it down to
something reasonable.

Change-Id: I6a136d1a739c782b368d5035db9bc25cf5b9599b
Signed-off-by: Jacob Garber <jgarber1@ualberta.ca>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/33944
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Reviewed-by: David Hendricks <david.hendricks@gmail.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>

util/inteltool/cpu.c

@@ -110,7 +110,7 @@ static msr_t rdmsr(int addr)
 
 static int open_and_seek(int cpu, unsigned long msr, int mode, int *fd)
 {
-	char dev[512];
+	char dev[32];
 	char temp_string[50];
 
 	snprintf(dev, sizeof(dev), "/dev/cpu/%d/msr", cpu);