Index: kernel/generic/src/printf/printf_core.c
===================================================================
--- kernel/generic/src/printf/printf_core.c	(revision eec616bc34e4233a5e002814ad0f802ef63af58d)
+++ kernel/generic/src/printf/printf_core.c	(revision e560ae83771ecf9be5a8ba952fb12d932672c732)
@@ -613,5 +613,6 @@
 			do {
 				i++;
-				switch ((uc = utf8_decode(fmt, &i, UTF8_NO_LIMIT)) != 0) {
+				uc = utf8_decode(fmt, &i, UTF8_NO_LIMIT);
+				switch (uc) {
 				case '#':
 					flags |= __PRINTF_FLAG_PREFIX;