sparse: fix all errors

sparse complains about cbprintf incompatible callback type and
incorrect size of struct __va_list. Add exceptions to silence those
errors.

Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>

include/zephyr/sys/cbprintf.h

@@ -155,7 +155,11 @@ BUILD_ASSERT(Z_IS_POW2(CBPRINTF_PACKAGE_ALIGNMENT));
  * int, or a negative error code that will be returned from
  * cbprintf().
  */
+#ifdef __CHECKER__
+typedef int (*cbprintf_cb)(int c, void *ctx);
+#else
 typedef int (*cbprintf_cb)(/* int c, void *ctx */);
+#endif
 
 /** @brief Signature for a external formatter function identical to cbvprintf.
  *

lib/os/cbprintf_packaged.c

@@ -38,7 +38,15 @@ static inline bool ptr_in_rodata(const char *addr)
  * va_list creation
  */
 
-#if defined(__aarch64__)
+#if defined(__CHECKER__)
+static int cbprintf_via_va_list(cbprintf_cb out,
+				cbvprintf_exteral_formatter_func formatter,
+				void *ctx,
+				const char *fmt, void *buf)
+{
+	return 0;
+}
+#elif defined(__aarch64__)
 /*
  * Reference:
  *