tree: Retype variable `programmer_may_write` with bool

Use the bool type instead of an integer for the variable
`programmer_may_write`, since this represents its purpose much better.

Signed-off-by: Felix Singer <felixsinger@posteo.net>
Change-Id: I69958527ae018a92f1c42734a7990d0c532dee0c
Original-Reviewed-on: https://review.coreboot.org/c/flashrom/+/66885
Original-Reviewed-by: Anastasia Klimchuk <aklm@chromium.org>
Original-Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/flashrom-stable/+/71483
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/chipset_enable.c b/chipset_enable.c
index 182410a..f781b16 100644
--- a/chipset_enable.c
+++ b/chipset_enable.c
@@ -26,6 +26,7 @@
 
 #define _LARGEFILE64_SOURCE
 
+#include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
@@ -1490,7 +1491,7 @@
 
 	if (err > 0) {
 		msg_pinfo("%d locks could not be disabled, disabling writes (reads may also fail).\n", err);
-		programmer_may_write = 0;
+		programmer_may_write = false;
 	}
 
 	reg = 0x88;