correctly declare log functions and fix potential formatstring injection

src/log.zig

@@ -39,5 +39,5 @@ fn syslog(
     };
     var buf: [1024]u8 = undefined;
     const str = try fmt.bufPrintZ(&buf, format, args);
-    c.syslog(priority, str.ptr);
+    c.syslog(priority, "%s", str.ptr);
 }

src/wayprompt-cli.zig

@@ -6,7 +6,10 @@ const debug = std.debug;
 const io = std.io;
 const meta = std.meta;
 
-pub const log = @import("log.zig").log;
+pub const std_options = struct {
+    pub const logFn = @import("log.zig").log;
+};
+
 const logger = std.log.scoped(.wayprompt);
 
 const Frontend = @import("Frontend.zig");

src/wayprompt-pinentry.zig

@@ -9,7 +9,10 @@ const fmt = std.fmt;
 const heap = std.heap;
 const debug = std.debug;
 
-pub const log = @import("log.zig").log;
+pub const std_options = struct {
+    pub const logFn = @import("log.zig").log;
+};
+
 const logger = std.log.scoped(.wayprompt);
 var use_syslog = &@import("log.zig").use_syslog;