fix(zmq): Corrected error bindings.

test_error/main.odin

@@ -0,0 +1,28 @@
+package main
+
+import "core:fmt"
+import "core:os"
+import "zmq"
+
+main :: proc() {
+	ctx := zmq.ctx_new()
+	defer zmq.ctx_term(ctx)
+
+	rep1, _ := zmq.socket(ctx, .REP)
+	defer zmq.close(rep1)
+	zmq.bind(rep1, "tcp://*:5555")
+
+	rep2, _ := zmq.socket(ctx, .REP)
+	defer zmq.close(rep2)
+	if err := zmq.bind(rep2, "tcp://*:5555"); err != nil {
+		fmt.eprintfln("bind failed: %s", zmq.strerror(err))
+		switch e in err {
+		case zmq.ZMQ_Error:
+			fmt.eprintfln("  variant: ZMQ_Error, member: %v", e)
+		case os.Platform_Error:
+			fmt.eprintfln("  variant: Platform_Error, member: %v", e)
+		case:
+			fmt.eprintfln("  variant: nil")
+		}
+	}
+}