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/flashrom.c b/flashrom.c
index 88a7402..f656872 100644
--- a/flashrom.c
+++ b/flashrom.c
@@ -56,7 +56,7 @@
 unsigned long flashbase;
 
 /* Is writing allowed with this programmer? */
-int programmer_may_write;
+bool programmer_may_write;
 
 #define SHUTDOWN_MAXFN 32
 static int shutdown_fn_count = 0;
@@ -158,7 +158,7 @@
 	/* Registering shutdown functions is now allowed. */
 	may_register_shutdown = true;
 	/* Default to allowing writes. Broken programmers set this to 0. */
-	programmer_may_write = 1;
+	programmer_may_write = true;
 
 	programmer_param = param;
 	msg_pdbg("Initializing %s programmer\n", programmer->name);