pxe: Move do_getfile() into the context

Rather than having a global variable, pass the function as part of the
context.

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 17ce54f..70dbde3 100644
--- a/cmd/pxe.c
+++ b/cmd/pxe.c
@@ -24,7 +24,7 @@
 	NULL
 };
 
-static int do_get_tftp(struct cmd_tbl *cmdtp, const char *file_path,
+static int do_get_tftp(struct pxe_context *ctx, const char *file_path,
 		       char *file_addr)
 {
 	char *tftp_argv[] = {"tftp", NULL, NULL, NULL};
@@ -32,7 +32,7 @@
 	tftp_argv[1] = file_addr;
 	tftp_argv[2] = (void *)file_path;
 
-	if (do_tftpb(cmdtp, 0, 3, tftp_argv))
+	if (do_tftpb(ctx->cmdtp, 0, 3, tftp_argv))
 		return -ENOENT;
 
 	return 1;
@@ -121,8 +121,7 @@
 	struct pxe_context ctx;
 	int err, i = 0;
 
-	pxe_setup_ctx(&ctx, cmdtp);
-	do_getfile = do_get_tftp;
+	pxe_setup_ctx(&ctx, cmdtp, do_get_tftp);
 
 	if (argc != 1)
 		return CMD_RET_USAGE;
@@ -176,8 +175,7 @@
 	char *pxefile_addr_str;
 	struct pxe_context ctx;
 
-	pxe_setup_ctx(&ctx, cmdtp);
-	do_getfile = do_get_tftp;
+	pxe_setup_ctx(&ctx, cmdtp, do_get_tftp);
 
 	if (argc == 1) {
 		pxefile_addr_str = from_env("pxefile_addr_r");