Avoid compiler warnings about the printf formats in IPv6 modules

[htibosch]

Description

As an option, the code in FreeRTOS+TCP can produce logging.

In three modules, my GNU compiler gives many warnings about the printf format used:

FreeRTOS_DHCPv6.c
FreeRTOS_IPv6_Utils.c
FreeRTOS_RA.c

For example in FreeRTOS_IPv6_Utils.c :

FreeRTOS_debug_printf( ( "%lu + %lu is larger than %lu\n",
                         uxIndex,
                         uxHopSize,
                         uxBufferLength ) );

gives 3 warnings of this type:

warning: format '%lu' expects argument of type 'long unsigned int',
but argument 3 has type 'size_t {aka unsigned int}' [-Wformat=]

In other modules, we solved this problem casting to either int or unsigned and using %u:

FreeRTOS_debug_printf( ( "%u + %u is larger than %u\n",
                         ( unsigned ) uxIndex,
                         ( unsigned ) uxHopSize,
                         ( unsigned ) uxBufferLength ) );

The logging is the same, and the warnings have gone, independent of the platform.

Earlier I wrote about my multi-platform testing of various printf formats.

Test Steps

Checklist:

• I have tested my changes. No regression in existing tests.
• I have modified and/or added unit-tests to cover the code changes in this Pull Request.

Related Issue

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[htibosch]

/bot run uncrustify