coding guidelines: comply with MISRA Rule 13.4

- avoid to use assignment expression value

Signed-off-by: Hess Nathan <nhess@baumer.com>

Author: DeHess

lib/os/cbprintf_complete.c

@@ -1060,7 +1060,7 @@ static char *encode_float(double value,
 			/* Fraction is subnormal.  Normalize it and correct
 			 * the exponent.
 			 */
-			while (((fract <<= 1) & BIT_63) == 0) {
+			for (fract <<= 1; (fract & BIT_63) == 0; fract <<= 1) {
 				expo--;
 			}
 		}

lib/utils/rb.c

@@ -537,7 +537,7 @@ static inline struct rbnode *stack_left_limb(struct rbnode *n,
 	f->stack[f->top] = n;
 	f->is_left[f->top] = 0U;
 
-	while ((n = get_child(n, 0U)) != NULL) {
+	for (n = get_child(n, 0U); n != NULL; n = get_child(n, 0U)) {
 		f->top++;
 		f->stack[f->top] = n;
 		f->is_left[f->top] = 1;