Fix typo: missmatched -> mismatched.

Signed-off-by: Vagrant Cascadian <vagrant@debian.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
diff --git a/tools/imx8image.c b/tools/imx8image.c
index 0d856b9..435f308 100644
--- a/tools/imx8image.c
+++ b/tools/imx8image.c
@@ -674,7 +674,7 @@
 			fclose(fd);
 
 			if (header.tag != IVT_HEADER_TAG_B0) {
-				fprintf(stderr, "header tag missmatched \n");
+				fprintf(stderr, "header tag mismatched \n");
 				exit(EXIT_FAILURE);
 			} else {
 				file_off +=