pxe: Tidy up the is_pxe global

Move this into the context to avoid a global variable. Also rename it
since the current name does not explain what it actually affects.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Artem Lapkin <email2tema@gmail.com>
Tested-by: Artem Lapkin <email2tema@gmail.com>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
diff --git a/cmd/pxe.c b/cmd/pxe.c
index d79b9b7..17fe364 100644
--- a/cmd/pxe.c
+++ b/cmd/pxe.c
@@ -121,7 +121,7 @@
 	struct pxe_context ctx;
 	int err, i = 0;
 
-	pxe_setup_ctx(&ctx, cmdtp, do_get_tftp, NULL);
+	pxe_setup_ctx(&ctx, cmdtp, do_get_tftp, NULL, false);
 
 	if (argc != 1)
 		return CMD_RET_USAGE;
@@ -175,7 +175,7 @@
 	char *pxefile_addr_str;
 	struct pxe_context ctx;
 
-	pxe_setup_ctx(&ctx, cmdtp, do_get_tftp, NULL);
+	pxe_setup_ctx(&ctx, cmdtp, do_get_tftp, NULL, false);
 
 	if (argc == 1) {
 		pxefile_addr_str = from_env("pxefile_addr_r");
@@ -235,8 +235,6 @@
 	if (argc < 2)
 		return CMD_RET_USAGE;
 
-	is_pxe = true;
-
 	/* drop initial "pxe" arg */
 	argc--;
 	argv++;